


UNITED STATES OF AMERICA. 




New Analytic Anatomy, Physiology and Hygiene. 



U?*M NEW ANALYTIC 



Anatomy, Physiology and Hygiene 



HUMAN AND COMPARATIVE. 



FOE COLLEGES, ACADEMIES AND FAMILIES. 



BY CALVIN CUTTER, M.D. 



WITH NUMEROUS ENGRAVINGS. 



PHILADELPHIA 
J. B. LIPPINCOTT & CO. 

1871. 



r> 



Entered according to Act of Congress, in the year 1S70, by 

CALVIN CUTTER, M.D., 

In the Office of the Librarian of Congress, at Washington. D. C. 



IIPPINCOTT'S PRESS 

PHIL AD KLPHIJ 



TO MY AFFECTIONATE WIFE, 
EUNICE P. CUTTER, 

WHO UNTIRINGLY AIDED ME IN THE PREPARATION OF MY FORMER 
WORK IN 1849, AND IN ITS REVISION IN 1852, 

AND TO OUR TWO SONS, 

JOHN CLARENCE CUTTER AND WALTER POWERS CUTTER, 

TRUSTING THAT THEY WILL SEE THAT ALL TIMELY REVISION AND 
EMENDATION ARE MADE IN FUTURE, TO MEET THE DE- 
MANDS OF INCREASING INTELLIGENCE, 

THJS TREATISE IS DEDICATED BY 

HUSBAND, FATHER AND AUTHOR. 



PREFACE 



The solicitation of my publishers, and the request of many 
teachers, have induced me to review and remodel my school- 
book on Outline Anatomy, Physiology and Hygiene, adapt- 
ing it to the advanced position of teachers, schools and the 
community. My former work was published in 1849, and 
thoroughly revised in 1852. Several hundred thousand 
copies of the revised edition have been published. It has 
been translated and published in five different languages, 
by the missionaries in Asia and Europe. 

In general arrangement, the present Treatise is modeled 
after the former. The aim has been to improve the analysis ; 
to bring the Chemistry and Histology to the present ad- 
vanced state of these sciences ; to make the Anatomy and 
Physiology concise and definite, the Hygiene plain and 
practical ; to introduce some Comparative Anatomy ; and to 
furnish illustrating cuts, both apposite and artistic. 

I am under great obligation to Joseph Leidy, M.D., of 
Philadelphia, who kindly permitted the use of his original 
illustrating cuts from his very valuable work upon Human 
Anatomy; also to the works of Marshall and Owen, and 
other scientific men, whose writings have been quoted and 
opinions adopted. 

As my physical frame is much enfeebled from wounds re- 
ceived while surgeon in the volunteer army, I am under 
l* 5 



6 PREFACE. 

special obligations to Miss Ada L. Howard, late Principal 
of the Ladies' Department of Knox College, not only for the 
ready pen, but for much detailed investigation, for simpli- 
fying the abstruse and erudite statements of our strictly 
scientific works, and for bringing into close contact, rela- 
tionship and harmony — in a word, unifying — what, without 
skillful combination, would be isolated and fragmentary. 

To the educational men and women, to all desiring know- 
ledge of themselves, physically, intellectually and morally, 
this small volume is respectfully submitted. 

Calvin Cutter. 

Warren, Mass., July, 1870. 



TO TEACHERS. 



Allow me to suggest that the method of study and in- 
struction of this work should be Analytical, with Synthetical 
Reviews ; that the Headings of the several chapters may be 
used as Topics ; that each subject should be thoroughly con- 
sidered, viewed in its relations to other subjects, and, if pos- 
sible, investigated beyond the limits of this elementary work ; 
that the Chemistry and Histology should receive due atten- 
tion, as the underlying basis of the Anatomy, Physiology 
and Hygiene ; that, as far as possible, the subject should be 
made an object study — the Chemistry, by simple experiments, 
the Anatomy, by examinations of parts of domestic animals ; 
also, that Outline Anatomical Diagrams or Charts are as 
desirable as a map in History or Geography ; that, in case 
of limited time or other necessity, the Comparative Anatomy, 
Histology and Chemistry, one or all, may be omitted (though 
with great loss to the pupil), and the remaining sections will 
be well adapted to each other. 



ANALYSIS OF CONTENTS. 



DIVISION I. 

CHAPTER I.— GENERAL REMARKS. 

SECT. PAGES 

« 1. The Three Kingdoms of Nature Compared 11-13 

2. Definitions 13,14 

* CHAPTER II.— GENERAL HISTOLOGY. 

3. Cells 14-17 

4. Tissues 17-25 

5. Membranes 25-30 

CHAPTER III.— GENERAL CHEMISTRY. 

6. Solids and Fluids 30-34 



DIVISION II. 

MOTORT APPARATUS. 

CHAPTER IV.— THE BONES. 

7. Anatomy of the Bones 36-47 

8. Histology of. 47-54 

9. Chemistry of. 54, 55 

10. Physiology of. 55-60 

11. Hygiene of 60-66 

12. Comparative Osteology 67-72 

CHAPTER V.— THE MUSCLES. 

13. Anatomy of the Muscles 73-79 

14. Histology of 79-81 

15. Chemistry of. 81,82 

16. Physiology of 83-89 

17. Hygiene of 89-98 

18. Comparative Myology 98-102 



DIVISION III. 
NUTRITIVE APPARATUS. 

CHAPTER VI.— THE DIGESTIVE ORGANS. 

19. Anatomy of the Digestive Organs 103-109 

20. Histology of 110-116 

21. Chemistry of 116-120 

22. Physiology of 120-122 

23. Hygiene of 122-131 

24. Comparative Splanchnology 131-137 

A* 9 



10 ANALYSIS OF CONTENTS. 



gECT> CHAPTER VII.— ABSORPTION. PAGES 

25. Anatomy of the Absorbents 138-141 

26. Histology of 141-143 

27. Chemistry of 143, 144 

28. Physiology of. 144-146 

29. Hygiene of. 146, 147 

CHAPTER VIII.— THE CIRCULATION. 

30. The Blood 148,149 

31. Anatomy of the Circulatory Organs 150-156 

32. Histology of 156-160 

33. Chemistry of 160-162 

34. Physiology of 162-168 

35. Hygiene of 168-172 

36. Comparative Angiology 172-175 

CHAPTER IX.— ASSIMILATION. 

37. Assimilation, General and Special 176-181 

CHAPTER X.— THE RESPIRATORY AND VOCAL ORGANS. 

38. Anatomy of the Respiratory and Vocal Organs 182-185 

39. Histology of .' 186-188 

40. Chemistry of 188-190 

41. Physiology of 190-196 

42. Hygiene of 197-205 

43. Comparative Pneumouology 205-209 



DIVISION IV. 
SENSORIAL APPARATUS. 
CHAPTER XI.— NERVOUS SYSTEM. 

44. Anatomy of the Nervous System 210-225 

45. Histology of. 225-228 

46. Physiology of 229-240 

47. Hygiene of. 240-252 

48. Comparative Neurology 252-259 

CHAPTER XII.— THE ORGANS OF SPECIAL SENSE. 

49. Anatomy of the Organs of Special Sense 260-281 

50. Physiology of. 281-288 

51. Hygiene of 289-298 

APPENDIX. 

CHAPTER XIII. 

Care of the Sick 299-303 

Poisons and their Antidotes 303-306 

Glossary 307-317 

Index 319-322 

For Treatment of Wounds, see ^ 363. For Recovery of Drowned Persons, see fl 430. 
For Treatment of Burns, see ^ 610. For Treatment of Frost-Bite, see % 612. 



Anatomy, Physiology and Hygiene. 



DIVISION I 



CHAPTER I. 

GENERAL REMARKS. 

\ 1. The Three Kingdoms of Nature Compared. — Essential dis- 
tinctions between the Mineral, Vegetable and Animal Kingdoms. — 
Nature of the Life-force. — Vitalized and Non-Vitalized Bodies com- 
pared. — Plants and Animals compared. 

1. " Lapides crescunt ; Vegetabilia crescunt et 
vivunt; Animalia crescunt, vivunt et sentiunt,"* 
was the Linnsean distinction between the three great king- 
doms of Nature. Though imperfect, it is still suggestive of 
the boundaries of each division. The Mineral kingdom in- 
cludes all things naturally destitute of life; the Vegetable 
kingdom, all organizations having a certain type of life, but 
no power to feel or to will ; the Animal kingdom, those pos- 
sessing a higher type of life and the powers of sensation and 
voluntary motion. 

2. Inorganic, or Mineral bodies are made up of atoms 
combined and arranged according to certain mechanical and 
chemical laws. Organic, or Vegetable and Animal 
bodies are combinations of like atoms, according to the same 
laws controlled by Vitality or the Life-force. Plants have a 

* " Stones grow ; Plants grow and live ; Animals grow, live and feel." 

11 



12 ANATOMY, PHYSIOLOGY AND HYGIENE. 

vegetable vitality — animals an animal vitality. Of the real 
character of this life-force we know nothing. Nature works 
in her inner laboratory with "No admittance" upon her 
door. We are at liberty to examine her products, but the 
mighty principle upon which they are wrought she holds fast 
as a secret unrevealable to us with our present limitations. 

3. Among the Distinctions between Organized, or Vital- 
ized, and Unorganized, or Non- Vitalized bodies, are the 
following : An Organized body consists of an assemblage of 
parts called organs, having a mutual relation to, and de- 
pendence upon, each other ; these taken together constitute 
an individual, a being; therefore the parts when separated 
are incomplete, as is seen in a divided plant. Not so with 
the Unorganized body : each fragment of a rock possesses all 
the essential characteristics of the original mass. Organized 
bodies, being subject to constant waste from vitalized activi- 
ties, demand nourishment; Unorganized bodies, being per- 
manent in their nature, require no food. Organized bodies 
grow by means of particles of matter conveyed to their in- 
terior and there assimilated; Unorganized bodies increase in 
size by simple layers upon the exterior : the former have a 
limit in size; the latter have no natural limit. Organized 
bodies have their period of duration : decay and death await 
every living animal and vegetable ; but, from the nature of 
the Inorganic world, we speak of the mountains as everlasting. 
Organized bodies have their particles arranged in lines gene- 
rally more or less curved, with varying angles, as in animals 
and plants; Unorganized bodies have their lines straight, 
with angles mathematically exact, as in the crystal of com- 
mon salt. Organized bodies reproduce themselves, each 
species after its own kind ; Unorganized bodies have no such 
power of reproduction. 

4. The Distinctions between Animals and Plants are im- 
portant. Animals take in oxygen and give out carbonic 
acid gas; Plants take in carbonic acid gas and give out 
oxygen. Animals subsist upon the products of the animal 
and vegetable kingdoms ; Plants, upon those of the mineral 



GENERAL REMARKS. 13 

kingdom. Animals, possess the power of sensation and volun- 
tary motion ; Plants, neither. 

5. These distinctions are obvious and definite in the higher 
grades ; but in the descending scale we recognize a gradual 
approach of plants and animals to each other, and likewise 
to the mineral kingdom ; so that, in the lower forms of life, 
all perceptible traces of organization disappear, and, like 
converging radii, the three kingdoms of Nature blend in one 
common centre. 

g 2. Definition of Terms. 

6. An organized body consists of parts called Or'gans. 
A collection of organs so arranged that their combined 
actions shall produce a given result is called an Apparatus. 
The definite, peculiar use of an organ or apparatus is called 
its Function : Example. — The digestive apparatus consists of 
the organs — teeth, stomach, liver, etc. — whose combined func- 
tions result in the digestion of food. 

The description of the form and position of these organs 
is called Anat'omy;* the description of their functions, 
Physiology ; f the examination of the conditions most 
favorable to their health, Hy'giene. J 

7. The organs are composed of a variety of structures, 
called Tissues, which are themselves composed of Cells. The 
description of the form, color, constituents and origin of 
these tissues and cells, or their minute anatomy, is called 
Histol'ogy;§ the science which treats of their ultimate ele- 
ments is called Chem'istry. || 

* Gr., ana, through, and tome, a cutting, 
f Gr., phusis, nature, and logos, a discourse. 
J Gr., hugieinon, health. 
. \ Gr., histos, a web, and logos, a discourse. 
II Ar., kimia, hidden art. 



CHAPTER II. 

GENERAL HISTOLOGY. 

2 3. Cells. — Unity of Plan exhibited in Plants and Animals. — Simple 
Cells. — Adaptation to Different Offices. — Modes of Multiplication. 

8. Wherever we find the work of the Infinite, there 
we find Unity of Plan. Whatever the extent of the applica- 
tions of this plan, whatever its modifications, there is still 
more or less apparent the distinct central idea. Amid the 
seemingly great diversity of substances in plants and ani- 
mals, there appears a beautiful and remarkable exhibit of 
this Unity. 

9. Protoplasm* is the formal basis of all living bodies. 
Animal Protoplasm, or Blastema,^ as it is often called, is an 
albuminous fluid, generally regarded as identical with the 
liquor sanguinis, or fluid portion of the blood, in which the 
red corpuscles are suspended. Floating in this protoplasm 
are numerous minute spheroidal cells, and an infinitude of 
smaller bodies having the appearance of dots called granules. 
From this organizable fluid every part of living beings is 
formed ; here is Unity of Substance. 

10. The simple Nucleated cell is the earliest organic form 
of every living thing, and increase of size is but an increase 
of the number of cells. There are sundry very low animals, 
each of which is structurally a nucleated cell, a colorless 
blood-corpuscle leading an independent life; a step higher 
come those which are little more than aggregations of similar 
cells ; and at length, as the vital functions become more and 
more differentiated, appear those with cells variously modi- 
fied, forming increasingly well-defined and complicated organs, 
till they seem to reach perfection in man. 

* Gr., protos, first, and plasma, formed. f Gr., blastos, a germ. 

14 



GENERA!^ HISTOLOGY. 15 

11. In the plant- world we find the same plan pursued ; 
under the microscope, the vegetable and the animal cell 
appear essentially the same, but they are by no means iden- 
tical. In examining the nucleoli of animal cells, little cir- 
cular bodies dart across the field of view. These seem to 
possess the power of voluntary movement ; and, had we the 
requisite refinement of sight, we should doubtless be able to 
classify even these minute bodies as accurately as we now do 
the fully-developed animal. In the vegetable cell these are 
never seen. 

Fig. 1. 




l 

Fig. 1 (Leidy). An Ideal Cell. — 1, Cell with its wall, protoplasm, nucleus and its 
nucleolus. 2, The same divided into two. 3, The same divided into four cells. 4, The 
same divided into many cells. The dark portion, the protoplasm ; the white spot, the 
nucleus ; the inner small circle, the nucleolus. Magnified. 

12. It appears, then, that the lowest and the highest 
organism — the fungus and man — have, in their earliest 
development, a unity of form of which the type is the 
simple cell. 

13. A Simple Cell consists of a delicate sac containing 
protoplasm, in which is another very minute sac, called the 
nu'cleus, which contains yet another sac — the nucleolus, or 
little nucleus. Very minute particles, or granules, are also 
seen. A good example of a simple animal cell, on a large 
scale, is an egg : the lining of the shell is the cell- wall or sac ; 
the white is the contained protoplasm; the yolk is the nu- 
cleus; and its germ-spot is the nucleolus. 

14. Cells in the course of their development are subject to 
numberless modifications — the animal cell, to subserve various 
purposes in the animal economy ; the vegetable cell, in the 
vegetable economy. As if under the immediate control of 
intelligence, they select each its own appropriate substance, 



16 ANATOMY, PHYSIOLOGY AND HYGIENE. 



rejecting all else. One set of cells has for its office the pro- 
duction of motion ; another set is for the purpose of secre- 
tion ; another, for assimilation ; another, for absorption ; still 
another, for reproduction; and so on, through all the dis- 
similar offices of the animal economy. 

15. Cells vary in size and shape ; the normal form is prob- 
ably spheroidal, as in cells of fat ; but they often become 
many-sided, sometimes flattened, as in the cuticle, and some- 
times elongated into a simple filament, as in fibrous tissue or 
muscular fibre. 



Fig. 2. 



Fig. 3. 





Fig. 2 (Leidy). Process of Multiplication, or Cartilage Cells.— 1, Simple cartilage 
cell from the embryo. 2, Increase of cartilage cells by division of the primary cell. 
3, 4, Groups of cartilage cells, from an adult articular cartilage. Magnified. 

Fig. 3 (Leidy). Process of Development of an Organic Cell from a Granule. — 
1, A granule. 2, A vesicle developed upon the granule ; the two constituting the nu- 
cleus and contained nucleolus. 3, The same, increased in size. 4, 5. Granules developed in 
the contained liquid of the nucleus. 6, The cell-wall developed on the nucleus. 7, 8, 9, 
Successive increase of the cell, and development of granular contents. Magnified. 

16. Cells multiply in three ways : 1st, A cell may elongate, 
contracting in the middle like an hour-glass or dumb-bell, by 
the infolding of the cell- wall, till a complete division is made 
and two cells are formed, each with its own share of the 
original nucleus ; the new cells divide in a similar manner, 
and like divisions are repeated indefinitely; 2d, Another 
form of multiplication is by the division of the nucleus 
within the cell; each part appropriates a portion of the fluid, 
and at length vesicles are formed, the old cell-wall breaks, 
and the vesicles develop into perfect cells; and 3d, Cells are 
sometimes developed de novo from the protoplasm, which 
contains nuclei and granules. 



GENERAL HISTOLOGY. 17 

17. Cells have their period of growth, of perfection and 
of decay. While the vital force directs and controls the 
chemical and mechanical agencies, they tend to preserve and 
build up the system ; but when the vital powers yield, they 
tend to its decay, and, " as if they were the grave-diggers of 
Nature^ fulfill the old motto — ' Earth to earth and dust to 
dust/" 

g,4. Primary Tissues. — Fibrous Tissue. — Areolar. — Cartilaginous. — 
Adipose. — Sclerous.— Muscular. — Tubular. — Nervous. 

18. By the various aggregations and transformations of 
cells the different tissues of the body are formed, and their 
individual characters depend upon the peculiar selecting 
power of these cells. 

19. The Primary Tissues are reducible to the following : 
the Fi'brous, the Areolar and the Cartilaginous, which, col- 
lectively, form the Connective tissues ; and the Ad'ipose, the 
Sclerous, the Mus'cular, the Tu'bular and the Ner'vous tissues. 

20. The object of the Connective tissues seems to be, 
mainly, that of binding together organs and their parts. It 
has few nerves and blood-vessels, and is, therefore, except 
when inflamed, nearly insensible, and attended with little 
hemorrhage under surgical operation. 

21. The Fibrous form of connective tissue is composed 
of minute filaments arranged in parallel and somewhat w r avy 
bundles, marked with faint cross-waves. It is strong, un- 
yielding and glistening. The fibrous tissue has two distinct 
forms — the White Fibrous and the Yellow Fibrous. 

22. The White Fibrous tissue is formed of white, glisten- 
ing, inelastic bands, having longitudinal creasings, but not 
admitting of separation into filaments of determinate size. 
This tissue, by long boiling, is entirely resolved into Gelatin. 
The white fibrous tissue is found under three forms : Mem!- 
brane, Lig'ament and Ten' don. 

23. The Yellow Fibrous tissue is composed of yellow 
elastic bands separable into their component filaments. It is 
called the Elas'tic tissue, elasticity being its chief charac- 

2* 



18 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



teristic. It does not gelatinize by boiling. It is found in the 
middle coat of the arteries, in the vocal cords, between the 
vertebrae, and in many other places where elasticity is needed. 
The proportion between the white and the yellow fibrous 
tissues, w 7 hen found together, varies — the greater the elasticity 
required, the greater the proportion of yellow elastic fibres. 



Fig. 4. 



Fig. 5. 





Fig. 4 (Leidy). Fibrous Tissue. — 1, Portion of tendon, exhibiting its composition of 
prismatic bundles of fibrous tissue, the filaments all parallel to one another. 2, A few 
bundles drawn from the others, exhibiting their union by delicate crossing filaments 
of connective tissue. 3, One of the varieties of fibrous tissue. 4, A single bundle, more 
highly magnified, with a portion (5) of the filaments fretted out. 

Fig. 5 (Leidy). Elastic Tissue. Highly magnified. 

Observation. — In rheumatism the connective white fibrous 
tissue is the part chiefly affected ; hence, the large joints and 
the loins, where this tissue is most abundant, suffer most. 
Where there is predisposition to rheumatism, the tendency to 
it may be lessened and attacks relieved by increasing the 
amount of clothing over the part affected. 

24. The Areolar form of connective tissue consists of 
bands of the fibrous, both of the white and yellow, which 
interweave in every direction, leaving open spaces between, 
called cells ; hence this tissue is sometimes named Cellular. 
These spaces communicate through the body, and contain a 
fluid resembling the serum of the blood. Although the con- 
nective areolar tissue enters into the composition of all organs, 
it never loses its individuality. In the nerves and muscles it 
shares neither the sensibility of the one nor the contractility 
of the other. 



GENERAL HISTOLOGY. 



19 



Observation. — The swelling of the feet so often seen in 
feeble persons shows the peculiarity of this tissue, which 
allows the fluid to pass from part to part and accumulate in 
the lowest portion of the body, while a recumbent position 
restores the original shape. Great excess of the fluid pro- 
duces general dropsy. The free communication between all 
parts of this tissue is still more remarkable in regard to air. 
Sometimes, when an accidental opening has been made from 
the air-cells of the lungs into the adjacent tissue, the air in 
respiration penetrates every part of the surrounding tissue, 
and even of the entire body, till inflation endangers life from 
suffocation. Butchers often avail themselves of this fact, 
inflating their meat to give it a fat appearance. 



Fig. 6. 



Fig. 7. 





Fig. 6 (Leidy). Portion of Connective Tissue, from the axilla, exhibiting its composi- 
tion of bundles and filaments of fibrous tissue crossing in every direction. The rounded 
bodies represent a single row and a portion of small groups of fat cells. Magnified. 

Fig. 7 (Leidy). 1, Portion of Connective Tissue, from that which envelops the flexor 
tendons of the fingers as they pass beneath the annular ligament, treated with acetic 
acid. The pale, dotted portion is intended to represent the fibrous element fading away ; 
the blacker, tortuous lines and nets represent the mixture of elastic tissue. 2, 3, Simple 
tortuous fibres and a net of elastic tissue. Magnified. 

25. Cartilaginous tissue consists of a solid mafrice, ap- 
parently homogeneous in structure, resembling ground glass. 
In this are imbedded nucleated cells, sometimes arranged 
simply, but usually in groups. It has no perceptible nerves 
nor blood-vessels. Cartilage is elastic and flexible, but in- 
extensible — qualities admirably essential to its use in the 



20 ANATOMY, PHYSIOLOGY AND HYGIENE. 

formation of the joints and in giving to other organs form 
and strength, without too much rigidity. This tissue consti- 
tutes the articular cartilages, the cartilage of the ribs, of the 
larynx (except the epiglottis), of the trachea and its divisions, 
and of the nose. The bones usually originate in cartilage, 
which disappears as bony matter is deposited ; such cartilage 
is called temporary ', while that which continues till later years 
is called permanent. 

Fig. 8. 




Fig. 8 (Leidy). Cartilage— section through the thickness of the oval cartilage of the 
nose. 1, Toward the exterior. 2, Toward the interior surface ; highly magnified. It 
exhibits groups of cartilage cells imbedded in a homogeneous matrice. 

Fig. 9. 




Fig. 9 (Leidy). Section of Fibro-Cartilage from the Auricle of the Ear. — The 
cells are seen imbedded in a fibrous matrice. 1, Exterior surface, where the cells are 
parallel to it. 2, Toward the middle. Highly magnified. 

26. When the matrice assumes a fibrous condition, Fibro- 
cartilages are formed, as in the intervertebral disks, the inter- 
articular cartilages, the epiglottis, the cartilages of the ear 
and Eustachian tube, and those of the eyelids. Between pure 
fibrous tissue and pure cartilage there are various degrees of 



GENERAL HISTOLOGY. 



21 



intermixture. Fibro-cartilage unites the elasticity of carti- 
lage with the toughness of fibrous tissue, and is therefore well 
adapted to the firmest union of bones accompanied with 
moderate flexibility. 

27. Adipose tissue has the peculiarity of not being essen- 
tial to the constitution of any organ. It is composed of deli- 
cate aggregated cells, of nearly spheroidal form, containing a 
substance called fat. It is found in the interspaces of areolar 
ti'ssue beneath the skin and around the heart and kidneys ; 
while none is ever found within the skull, the lungs and the 
eyelids, where its presence would interfere with their several 

Fig. 10. 





Fig. 10 (Leidy). Crossing Bands of fibrous connective tissue. 

Fig. 11 (Leidy). Adipose Tissue, with Connective Tissue, from the superficial fascia 
of the abdomen ; highly magnified. The groups of fat vesicles are observed contained 
in the meshes of connective tissue. 



functions. Fat accumulates more readily than other matter, 
and is the earliest removed in disease. It is a storehouse of 
nutriment, always ready for use, and a non-conductor of heat ; 
it also gives roundness and beauty to the form. 

28. Sclerous tissue is found in the bones and teeth. .Its 
composition and arrangement vary at different periods of life. 



22 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



29. Muscular tissue is composed of fibres, which are 
themselves composed of minute fibres, called ftbrillce, or fila- 
ments. The fibres of this tissue are of two kinds — non- 
striated and striated. The former are soft, pale, smooth, either 
roundish or flattened, and indistinctly granulated, having no 
markings, or striae ; the latter are soft, yellowish, prismatic, 
and composed of quadrangular particles so arranged as to 
give transverse striae. This tissue has for its peculiar charac- 



Fig. 12. 



Fig. 13. 





Fig. 12 (Leidy). Fibrils from a Muscular Fibre of the Axolotl, a Batrachian 
Reptile ; highly magnified, a, Bundle of fibrils. 5, An isolated fibre. 

Fig. 13 (Leidy). Two Portions of a Muscular Fasciculus, from the trapezius 
muscle; highly magnified. 1, Two portions of a muscular fasciculus, composed of 
prismatic striated fibres terminating below, in rounded extremities, among the fibrous 
tissue of the commencing tendon. 2, Cut extremities of the fibres, showing their 
prismatic form. 3, Delicate sheath, composed of obliquely-crossing filaments of fibrous 
tissue. 4, The fibres of the commencing tendons. Partly a diagram. 



teristic, contractility, and is the instrument upon which the 
sensible motions of the body depend. It is a good conductor 
of electricity, and very sensitive to that agent. It has within 
itself constant electrical currents, called, collectively, the mus- 
cular current 

30. Tubular tissue consists of a network of minute tubes, 



GENERAL HISTOLOGY. 



23 



called cap'illary* vessels. These vessels connect the terminal 
extremities of the arteries with the commencement of the 
veins, but are otherwise closed, and never communicate ex- 
cept by imbibition with the structures through which they 
pass. Their walls are composed of exceedingly thin, trans- 
parent, structureless membrane containing scattered nuclei. 
They vary in size, being largest in the bones, and smallest in 
the brain and in the lungs. This tissue is found in all 
parts of the body, excepting the substance of the teeth, the 
cartilage of the joints, the transparent part of the eye, the 
epithelial tissue, the hair and the nails. 



Fig. 14. 



Fig. 15. 





Fig. 14 (After Wagner.) A Piece of the Web of a Frog's Foot, slightly enlarged, 
showing the fine capillary network connecting the terminations of the arteries with the 
commencement of the veins. 

Fig. 15 (Allen Thomson). Minute Piece of the Margin of the Frog's Web, show- 
ing the ultimate capillaries, connecting the end of a small artery with the beginning 
of a minute vein. The oval blood-corpuscles are seen in these vessels, and the arrows 
entering and passing out of the artery and vein indicate the course of the blood-current ; 
magnified about thirty diameters. 

31. The Nervous tissue is distinguished from all other 
tissues by its sensibility. Like the muscular tissue, it has 
constant electrical currents. It forms the essential substance 
of the brain, spinal cord and nerves. This tissue contains 



* Lat.j capillus, a hair. 



24 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



three distinct microscopical elements — Nerve- Cells, or Gang- 
lionic Corpuscles; Gray or Gelatinous fibres; and White or 
Tubular fibres. 



Fig. 16. 




Fig. 16 (Kolliker and Hannover). 1, Nucleated cells from a sympathetic ganglion. 
2, Branched or stellate cells from the gray substance of the spinal cord. 3, Branched 
cells from the medulla oblongata. 4, Simple and branched cells from the convolutions 
of the brain. 5, A large cell from the gray substance of the brain ; magnified one hun- 
dred diameters. 

Fig. 17. 




Fig. 17. Diagram of Human Brain, in Vertical Section, showing the situation of 
the different ganglia and the course of the fibres. 1, Olfactory ganglion. 2, Hemisphere. 
3, Corpus striatum. 4, Optic thalamus. 5, Tubercula quadrigemina. 6, Cerebellum. 
7, Ganglion of tuber annulare. 8, Ganglion of medulla oblongata. 

32. The Ganglionic Corpuscles are cell-bodies contain- 
ing pulpy matter, with one or more nuclei surrounding 
colored granules. These cells vary in shape, being roundish, 
pear-shaped, or branched in a caudate or stellate manner, these 
offsets being continuous with the cell-wall and its contents, and 



GENERAL HISTOLOGY. 25 

often entering another cell and connecting the two. These 
nerve-cells are found in the brain, spinal cord and ganglia, 
and at the extremities of the nerves of sight and hearing. 

33. The Gray or Gelatinous fibres are soft and granular, 
with no distinct medullary sheath. They contain many dark 
nuclei, and are most abundant in the sympathetic ganglia 
and* its branches. 

34. The White or Tubular fibres are microscopic tubes. 
The walls are structureless membrane enclosing a layer of 
medullated matter resembling fluid fat, which acts as a sheath ; 
within this is a firmer part, or core, called the band-axis, or 
axis cylinder ; this is albuminous. 

35. The gray substance is most abundant in the outer part 
of the brain, and the white in the inner ; but the two intermix 
more or less in every part of the nervous system. 

? 5. Membranes. — Basement Membrane. — Epithelium. — Serous Mem- 
brane. — Synovial Membrane. 

36. Basement Membrane is an exceedingly thin, deli- 
cate, structureless layer of protoplasm or blastema, resem- 
bling, under the microscope, a film of transparent gelatine. 
Upon it, in various parts of the body, are imbedded minute 
epithelial* cells. The membrane formed by these cells is 
called epithelium. The relation of this structureless mem- 
brane to the epithelium gives it the name of Basement Mem- 
brane. 

Fig. 18. 




Fig. 18 (Leidy). Diagram exhibiting thk Relative Position of the Common Ana- 
tomical Elements of Serous and Mucous Membranes, the Glands, the Lungs and 
the Skin. — 1, Epithelium, secreting cells or epidermis, composed of nucleated cells, and 
occupying the free surface of the structure mentioned. 2, Basement layer, represented 
much thicker than natural, in comparison with the other layers. 3, Fibrous layer, in 
which the arteries and veins (4) terminate in a capillary network. Magnified. 



Gr., epi, upon, and tithemi, I cover or place. 
B 



26 ANATOMY, PHYSIOLOGY AND HYGIENE. 

37. From difference in form and other peculiarities, the 
Epithelium is divided into several varieties — as the Squa- 
mous Epithelium, consisting of several layers of thin scales, 
which are flattened cells having a nucleus and a few scat- 
tered granules, as in the mucous membrane of the mouth ; 
the Pavement Epithelium, consisting of from one to four 
layers of nucleated cells, six-sided and regularly arranged 
like the blocks of a pavement (whence the name), as in the 
serous membranes ; the Columnar Epithelium, consisting of a 

Fig. 19. 





Fjg. 19 (Leidy). Squamous Epithklium, consisting of nucleated cells transformed into 
broad scales, from the mucous membrane of the mouth ; highly magnified. 

Fig. 20 {Leidy). Pavement Epithelium, from a serous membrane, highly magnified, 
and seen to consist of flat, six-sided nucleated cells. 

single layer of six-sided columnar cells, with a conical pro- 
longation terminating in a progeny of developing cells, as 
in the mucous membrane of the stomach and intestines ; 
the Ciliated Epithelium, having cells possessing at their 
free extremity fine filamentary processes of the cell-wall, 
resembling the eye-lashes (whence the name). During life 
these cilia are endowed with a power of moving rapidly 
backward and forward in a wave-like manner, reminding 
one of the movement of a field of grain swept by a gentle 
breeze. Currents are thus produced in liquids, conveying 
them from one part to another. This kind of epithelium is 
found on the mucous membrane of the upper part of the 
nose and pharynx, the Eustachian tube and all the respira- 
tory organs. 

38. Beneath the basement membrane, and in contact with 
it, is a very dense and vascular layer of areolar and elastic 
tissue. This triple arrangement of epithelium, basement 
membrane and fibro-areolar tissue, constitutes the serous, the 



GENERAL HISTOLOGY. 



27 



synovial and the mucous membranes, the skin, the ducts of 
all glands, and the inner coat of the blood-vessels and the 
lymphatics. 

39. The Serous Membrane is that portion which lines 
the walls of certain closed cavities or sacs. It is smooth, 
shining and moistened by a fluid called se'rum, which the 
membrane secretes ; as the pleura, peritoneum, pericardium, 
arach'noid, etc. 



Fig. 21. 



Fig. 22. 





Fig. 21 (Leidy). Diagram of a Vertical Section of the Mucous Membrane of the 
Small Intestines ; highly magnified. 1, Fibrous layer, in which the blood-vessels are 
distributed. 2, Basement membrane. 3, Young nucleated cells. 4, Layer of columnar 
cells. 5, 6, Cells in the act of being shed or thrown off. 7, Free ends of the columnar 
cells, exhibiting their six-sided form. 8, A single columnar cell, exhibiting its actual 
form at all parts. 

Fig. 22. Diagram of a Vertical Section of the Bronchial Mucous Membrane. — 
1, Columnar ciliated epithelial cells. 2, Cilia. 3, Nuclei. 4, Young cells. 5, Basement 
membrane. 6, Fibrous layer. 

40. The Synovial Membrane resembles the serous very 
closely as regards structure and the closed sacs. It also 
secretes a fluid, called syno'via, which is more viscid than that 
of the serous membrane. It has fringe-like processes hanging 
loosely in the joints, having large epithelial cells, which prob- 
ably secrete the synovial fluid. This membrane covers the 
cartilages, and lines the ligaments which enter into the com- 
position of the joints. 

Observat ion.— When the synovial membrane is ruptured, 
the synovia escapes into the surrounding areolar tissue, and 
what is popularly known as the " weeping sinew" is formed. 



28 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



Similar tumors in the joints of lower animals are called 
" windgalls." 

41. There are two Mucous Membranes — the Gastro-Pul- 
monary and the Urinary. These do not form closed sacs, like 
the serous and synovial membranes, but both open to the 
surface. The mucous membranes secrete a viscid fluid, called 
mucus, and in their glandular recesses are formed various 
secretions, as saliva, bile, tears, etc. These membranes vary 
in different parts both in thickness and appearance. In the 
nasal and air passages, the membrane is smooth, rugose or 
ridgy in the stomach, papillous in the tongue and villous in 
the intestines. 



Fig. 23. 



Fig. 24. 





Fig. 23 {Leidy). Diagram exhibiting the Relation of a Serous Membrane (the 
pleura) to the Organ it Invests and the Cavity it Lines.— 1, Lung. 2, Root of the 
lung, which is the only attached portion of the organ, all others being free. 3, Side of 
the thorax. 4, Diaphragm. 5, Parietal pleura. 6, Pulmonary or reflected pleura. 
7, Cavity of the pleura. Magnified. 

Fig. 24 (Leidy). Mucous Membrane from the Jejunum. — 1, Villi resembling val- 
vule conniventes in miniature. 2, Tubular glands : their orifices. 3, Opening on the 
free surface of the mucous membrane. 4, Fibrous tissue. Magnified. 

42. The Gastro-Pulmonary Mucous membrane com- 
mences at the mouth, enters the nostrils, passes between the 
eyelids, dips into the deep parts of the ear, lines the trachea 
and the air-tubes of the lungs, and the alimentary canal from 
one extremity to the other. 

43. The Urinary Mucous membrane lines the ducts con- 
necting the kidneys and the bladder, of which it forms the 
interior coat ; also the passages to the skin. 



GENERAL HISTOLOGY. 29 

44. The skin is continuous with the mucous membranes, 
and will be described hereafter. 

Observation. — Like tissues readily assume similar con- 
ditions ; hence diseases of the skin or of the serous or mucous 
membranes are often transferred from one to the other. In 
diseases of the skin — as measles, scarlet fever, etc. — if the 
surface becomes damp or chilled, there is danger of their 
being transferred to the mucous membrane of the air-passages, 
stomach or intestines. In chronic diseases of the mucous 
membrane — as coughs, catarrh, diarrhoea or dysentery — the 
skin is usually cold, dry and inactive. By improving its 
condition much relief will be afforded. 
3* 



CHAPTER III. 

GENERAL CHEMISTRY. 

§ 6. Solids and Fluids. — Proximate Constituents. — Inorganic. — Organic. 
— Nitrogenous. — Non- Nitrogenous. — Ultimate Chemical Elements. 

45. The human body is composed of solids and fluids, re- 
ducible, by chemical analysis, to the same constituents and 
elements. In different periods of life the proportion of fluids 
and solids varies ; the former being more abundant in youth 
than in old age. This is one reason why the limbs in child- 
hood are soft and smooth, but in later years hard and wrinkled. 

46. If the tissues of the body are subjected to chemical 
analysis, they yield about ninety substances, called Proximate 
Constituents, these being the first chemical compounds into 
which the tissues resolve themselves. In living beings 
vitality is, as it were, " the architect who plans the building 
and sees that the requisite materials are procured by the 
chemical processes and worked up according to his will." 
Hereupon arise many new substances which cannot be arti- 
ficially imitated ; these are called Organic proximate con- 
stituents. Those substances found in the inorganic kingdom 
also, and capable of artificial imitation, -are called Inorganic 
proximate constituents. 

47. Of the Inorganic Proximate Constituents, water 
is the most abundant: it exists in all the tissues; next to 
this, in relative quantities, are Phosphates of Lime, of Mag- 
ne'sia, of Soda and of Potas'sa ; Carbonates of Lime, of Soda 
and of Potassa ; Chloride of Sodium (common Salt) and of 
Potassium ; and Fluoride of Cal'cium. Some compounds 
contain Iron, Sil'ica, Manganese', and perhaps some acci- 
dental substances, as Lead, Copper and Alu'minum. Am- 

30 



GENERAL. CHEMISTRY. 31 

rno'nia, in combination, is found in the urine. Ox'ygen, 
Xi'trogen and Carbon'ic Acid gas exist in a free state. 

48. The Organic Proximate Constituents are of two 
classes. One class contains the chemical element Azote',* or 
nitrogen; hence its compounds are called az'otized or nitrog- 
enous; the other has no azote, and its compounds are named 
non-jxzotized or non-nitrogenous. 

49. The Nitrogenous class contains Albu'men and its 
allied substances, called albuminoids. Some of the most im- 
portant are — Albuminose, Fibrin, Miisculin, Glob'ulin, Hcem'a- 
tin, Casein, Cartild gin, Sal'ivin, Pep sin, Paneredtin, Mucin, 
Neu f rin, Keratin, Elas'tin, Mela'nin and Biliverd'in; also 
some acids, as the Cer'ebric, Clwl'ic and U'ric. 

50. Albumen and the albuminoids, together with fatty- 
matter (non-nitrogenous), are the great nutritive substances 
of the animal economy. Albumen t is well known in the 
white of an egg; whence its name. It is found in the sub- 
stance of the brain and nerves ; in the fluid part of the blood ; 
in the moisture that pervades the muscles and other tissues ; 
in the lymph and chyle; and in the mucous, serous and 
synovial secretions. It coagulates by the action of heat and 
alcohol, and is dissolved by weak acids and alkalies. 

51. Albuminose is found in the chyle and blood in a 
liquid condition, and is a result of the digestion of albu- 
minous, fibrinous, musculinous and caseous matter of food ; 
unlike albumen, it is not coagulated by heat. 

52. Fibrin is a soft, white, stringy substance, obtained 
from freshly-drawn blood by whipping it with fine sticks or 
wires. It < coagulates spontaneously, assuming the form of 
minute threads, or fibrils ;J wdience its name. Fibrin is also 
found in the chyle, lymph and serous secretions. It is pre- 
cipitated and hardened by alcohol, and redissolved by weak 
acid. 

53. Musculin is a peculiar form of fibrin that exists in 

* Gi\, a, not, and zoe, life. f Lat., albas, white. 

J Lat., JJ&res, a thread. 



32 

the muscles, or flesh. Its characteristic property is con- 
tractility. Boiling hardens it, while weak ^ acids render it 
more soluble. 

54. Globulin and H^ematin form the contents of the red 
globules of the blood. Hsematin contains about seven per 
cent, of iron ; but the color of the blood is now supposed not to 
depend on the iron, but a peculiar substance named cruorin. 

55. Casein resembles albumen in its general properties, 
but, unlike albumen, when in solution it is not coagulated 
by heat, but by acids. It exists in solution in milk with 
lac tin (milk sugar) and salts. It forms the curd in soured 
milk, the casein being coagulated by the lactic acid formed 
from decomposed lactin. 

56. Cartilagin is the principal constituent of the con- 
nective tissues, as the so-called bone cartilage, true cartilage, 
ligaments, tendons, fibrous membranes, dermis and the areo- 
lar tissue. The basis of bone cartilage is os'teine, with which 
are blended salts of lime. The basis of true cartilage is 
called chon'drigen. Unlike albumen, cartilagin is* insoluble 
in water and does not coagulate by heat, but is liquified by 
boiling and changed into gel'atin, or glue. 

57. Salivin is found in the saliva. It has the peculiar 
property of changing starch into a kind of gum called dex'- 
trine, the dextrine into gla'cose, or grape sugar, and this into 
lactic acid. 

58. Pepsin is a remarkable and potent substance secreted 
by the glands of the mucous membrane of the stomach. This 
secretion is a peculiar principle of the gastric juice, and, 
when slightly acidulated, has the property of quickly dis- 
solving coagulated albumen, blood, meats, fish, cheese and 
many other substances. 

59. Pancreatin is the active principle of the secretion of 
the pancreas. It has three distinct actions — 1st, on starch ; 
2d, on fat ; and 3d, on albuminous matter. 

60. Mucin is a substance found in the different varieties 
of mucus, imparting to them their viscid character. It is 
usually mixed with other fluids. 



GENERAL CHEMISTRY. 33 

61. Neurin is also an albuminoid substance connected 
with the brain and nerves, upon which the peculiar charac- 
teristics of the nervous system are supposed to depend. 

62. Keratin is the peculiar albuminoid principle giving 
the horn-like character to the hair, nails and cuticle. 

63. Elastin is the substance peculiar to the elastic tissue. 
It is insoluble in all common fluids. 

64. Melanin is a blackish-brown coloring matter found 
in the choroid coat and the iris of the eye, in the hair and in 
the epidermis. It is most abundant in the black and brown 
races, but it also exists in the yellow and white races. 

65. Biliverdin is the coloring matter of the bile. It is 
yellow in transmitted light, and greenish in reflected light. 
On exposure to the air in its natural fluid condition, it ab- 
sorbs oxygen and assumes a bright grass-green color. 

66. Beside the before-mentioned constituents, none of which 
are acid but mucin, there are several acids, among which 
may be named the Cerebric acid found in the gray substance 
of the brain ; Cholic acid in the bile ; and Uric acid in the 
urine. 

67. The groups of non-nitrogenized or non-azotized sub- 
stances are — the fats, sugars and starch. The fats are most 
abundant. These are insoluble in water, but are dissolved 
by heat, alcohol and ether. They are found in the brain, 
muscles, blood and chyle. 

68. The Fats of the human body are composed mostly of 
o'lein (liquid fat), and stearin and mar' gar in (solid fats), mar- 
garin being most abundant, and stearin least. The fats are 
derived from the fatty components of food, and also from 
transformed saccharine compounds. When boiled with an 
alkali, as in the manufacture of soap, they decompose into 
fatty acids, margaric, stearic and oleic acids, and a sweet, 
viscid substance called glyc'erine. 

69. Sugars are of different kinds, as Glu'cose (grape sugar), 
in the blood and chyle ; Liver sugar, in the liver ; Lac'tin 
(milk sugar), in milk ; In'osit (muscle sugar), in muscles. 
Lactin, in contact with azotized matter, or a ferment, easily 



34 ANATOMY, PHYSIOLOGY AND HYGIENE. 

decomposes, forming lactic acid. All these saccharine and 
acid substances are soluble in both water and alcohol. 
Starch granules are found in the brain, and are named 
Corpora Amyla'cea. These exhibit the chemical reactions 
of vegetable starch, and are colorless and transparent, re- 
sembling in appearance the granules of Indian corn. 

70. The Ultimate Chemical Elements enter into the 
composition of the body in about the following percentage 
proportions : 

Gases. Oxygen 72. 

Hydrogen 9.1 

Nitrogen 2.5 

Chlorine 085 

Fluorine 08 

Solids. Carbon 13.5 

Phosphorus 1.15 

Calcium 1.3 

Sulphur 1476 

Sodium 1 

Potassium 026 

Iron 01 

Magnesium 0012 

Silicon .0002 

100.0000 

71. The greater part of the oxygen and hydrogen exist in 
a state of water, but the dried residue still , contains some 
gaseous as well as solid elements. 

72. Carbon is the most abundant element. In the in- 
evitable decomposition of the body, while its hydrogen and 
nitrogen, with part of its carbon and oxygen, are restored to 
the inorganic world in the shape of water, carbonic acid and 
ammonia, the rest of its carbon and oxygen, its chlorine and 
fluorine, its phosphorus and sulphur, and its metallic bases, 
calcium, sodium, potassium, magnesium and iron, with a trace 
of silicon and manganese, revert to the condition of inorganic 
salts and earths — viz., carbonates, sulphates and phosphates, 
chlorides and fluorides of the above-named saline and earthy 
bases. 



THE BONES, 



35 



FitJ. 25. 




DIVISION II. 

MOTOEY APPARATUS. 

73. In all the movements connected with the merriments 
of childhood, with the ceaseless industry of the telling mil- 
lions, with the hymning of the praises of the great I Am, — 
in a word, in every movement of the body, certain organs are 
brought into action, which, taken collectively, constitute the 
Motory Apparatus. The organs of this apparatus are the 
Bones and Joints, the Muscles and Motor Nerves. 



CHAPTER IV. 

THE BONES. 



I 7. Anatomy of the Bones. — The Skeleton and its Uses. — Number 
and Classification of the Bones. — Bones of the Head. — Of the Trunk. — 
Of the Upper Extremities. — Of the Lower Extremities. — The Joints. — 
Definition and Classification, — Immovable Joints. — Mixed. — Movable. 
— Peculiar Forms of Movable. 

74. The Internal Framework of the human body con- 
sists of Bones, which, united by strong ligaments,* constitute 
the Skeleton. 

75. These bones number two hundred and eight, besides 
the teeth. For convenience they are classed as the bones of 
the Head, the Trunk and the Extremities. 

76. The Bones of the Head are divided into those of 
the Skull, the Face and the Ear. 

77. The Skull is composed of eight bones — the Frontal, 
occupying the portion called the forehead ; the two Temporal, 

* Lat., ligo y I bind. 
36 



THE BONES. 



37 



covering the part commonly known as the temples ; the two 
Parietal, forming the essential part of the projection on the 
upper and lateral parts of the head and uniting in the median 
line upon the top of the skull ; the Occip'ital, at the posterior 
part of the skull, resting upon the atlas vertebra and having 
a large orifice for the passage of the spinal marrow; the 
Sphenoid, situated across the base of the skull, extending 
from side to side, having many depressions and processes, 
articulating with all the bones of the cranium and five of 
those in the face, and serving as a point of attachment for 
twelve pairs of muscles ; and the Eth'moid bone, between the 
sockets of the eves and behind the base of the nose. 



Fig. 26. 




Fig. 26. Bones of the Head. — 1, Frontal bone. 2, Parietal bone. 3, Temporal bone. 
4, Occipital bone. 5, Nasal bone. 6, Malar bone. 7, Upper jaw. 8, Os unguis. 
9, Lower jaw. 

78. The skull-bones are formed of two plates united by 
porous bone-substance. The external plate is fibrous and 
tough ; the internal, dense and hard, hence called the vitreous 
or glassy plate. These bones are united by sutures; the ex- 
ternal plate having notched edges fitted together as in the 
dovetailing of carpentry ; the internal, plane edges in simple 



38 ANATOMY, PHYSIOLOGY AND HYGIENE. 

apposition. From infancy to the twelfth year the sutures 
are imperfect ; from that time to forty, distinctly marked ; 
and in old age, nearly obliterated. 

Observation. — We find no less diversity in the form and 
texture of the skull than in the expression of the face. The 
head of the New Hollander is small, that of the African is 
compressed, while that of the Caucasian is distinguished for 
its beautiful oval form. In texture the Greek skull is close 
and fine, while the Swiss is softer and more open. 

79. The Face has fourteen bones — the two No! sal, forming 
the bridge or base of the nose ; the two Malar (cheek-bones) ; 
the two Lach'rymal; the two Siqierior Mamillary, articulating 
with two bones of the skull and all the bones of the face ex- 
cepting the lower jaw; the two Palate bones, forming the 
orbits of the eyes, the outside of the nose, and the most of the 
roof of the mouth known as the hard palate ; the two Tur- 
binated, in the nostrils ; the Inferior Maxillary, or mandible, 
the only movable bone of the face, articulating with the tem- 
poral bones ; and the Vo'mer, which separates the nostrils 
from each other. 

80. The Ear has three small bones, which aid in hearing. 

81. The Bones of the Trunk number fifty-four — twenty- 
four Ribs; twenty-four bones in the Spinal Column; four in 
the Pel' vis; the Sternum (breast-bone) ; and the Os Hyoi'des 
(at the base of the tongue). These bones, with the soft parts 
attached, are so arranged as to form two cavities, called the 
Tho'rax (chest) and the Ab'domen. 

82. The Thorax is formed by the sternum in front, the 
ribs at the sides and the twelve dorsal vertebrae at the back. 
The natural form of the chest is conical, with the apex above ; 
but fashion, in a multitude of instances, has inverted the 
order. The thorax contains the heart, the lungs and the 
large blood-vessels. 

83. The Sternum is situated in the middle line of the 
front of the chest, and is held in place chiefly by the ribs. 
Each side is marked by seven pits for receiving the cartilages 
of the corresponding true ribs. In childhood the sternum 



THE BOXES. 39 

consists of several cartilaginous pieces, which ossify and 
unite in later years. 

84. The Ribs are connected with the spinal column, twelve 
on each side. The first seven, called True ribs, are connected 
with the sternum by means of cartilage ; of the remaining 
five, called False ribs, three are connected by cartilage with 
each other, while the two lower are free at their anterior ex- 
tremity, hence called floating ribs. In length, the ribs in- 
crease from the first to the eighth, then again diminish to 
the twelfth ; in breadth, they gradually diminish from the 
first to the last ; in direction, the first rib is horizontal, all 
the others are oblique and downward. 




Iig. 27. The Front View of the Thorax. — 1, 2, 3, The sternum. 4, 5, The spinal 
column. 6, 7, 8, 9, The first rips. 10, The seventh rib. 11, Cartilage of the third rib. 
12, The floating rib. 

85. The Spinal Column is composed of twenty-four bones, 
called Vert'ebrce. Each vertebra consists of a main part, 
called the body, and seven projections, called processes; four 
of these, employed in binding the bones together, are called 
articulatory ; two of the remaining, transverse; and the other, 



40 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



spinous. The last three give attachment to the muscles of 
the back. The projections are so arranged that immediately 
behind the bodies of the vertebrae a canal is formed for the 
Medul'la Spina'lis (spinal cord), sometimes called the pith of 
the back-bone. 

86. The Vertebrae are arranged in three classes, accord- 
ing to their situation ; the seven of the neck are called Cervi- 
cal; the twelve of the back, Dor sal; and the five of the loins, 
Lumbar vertebrae. 



Fig. 28. 



Fig. 29. 



3 3 



"4 




Fig. 28. The Spinal Column, Lateral view. 1, 2, 3, The vertebrae. 4, Sacrum. 
5, Coccyx. 
Fig. 29. The Chest and Pelvis, Front view. 

87. The Cervical Vertebrae are smaller than those of 
other regions; they are concave above and convex below; 
hence, when articulated, they lock one into the other. The 
processes are short, bifid and horizontal, permitting a par- 
tial rotary movement. The upper vertebra articulating 
with the occipital bone is called the At' las; the second, the 
Ax'is. 

88. The Dorsal Vertebrae furnish support for the ribs, 



THE BONES. 



41 



which are so connected with the transverse processes as to 
impede rotation. The spinous processes are very long and 
extend obliquely downward. The bodies are larger than 
those of the cervical vertebrae, and increase in size according 
to the weight to be sustained. 

89. The Lumbar Vertebra have broad bases, with 
large, strong and horizontal processes. These vertebrae show 
those transitional changes which are calculated, by an easy 
gradation, to unite separate vertebrae into solid bone. 



Fig. 30. 



Fig. 31. 





Fig. 30. A Vertebra of the Neck. — 1, The body of the vertebra. 2, The spinal canal. 
4, The spinous process, cleft at its extremity. 5, The transverse process. 7, The inferior 
articulating process. 8, The superior articulating process. 

Fig. 31. A Cervical Vertebra. — 1, The cartilaginous substance that connects the 
bodies of the vertebra?. 2, The body of the vertebra. 3, The spinous process. 4, 4, The 
transverse processes. 5, 5, The articulating processes. 6, 6, A portion of the bony bridge 
or arch that assists in forming the spinal canal (7). 

90. Covering the front of the bodies of the vertebrae is the 
Anterior Vertebral Ligament, consisting of a broad range of 
fibres closely blended and of variable length. This ligament, 
besides joining the vertebrse firmly together, gives attach- 
ment to the pharynx, the oesophagus, the thoracic duct, the 
aorta and other large blood-vessels. On the posterior part 
of the bodies of the vertebrae, within the spinal canal, is 
the Posterior Vertebral Ligament, remarkably smooth and 
shining. Both the anterior and posterior ligaments adhere 
very closely to the intervertebral substance and to the bodies 
of the vertebrse. 

91. Between the arches of the vertebrae behind, are the 
4 s 



42 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



Yellow Ligaments {Ligamenta Subflava), filling up the intervals 
and completing the spinal canal from the axis to the sacrum ; 
they are two in number on each side, making twenty-three 
pairs. They are attached to the anterior surface of the lower 
part of the arches above and the posterior surface of the 
upper part of those below, between the spinous and the trans- 
verse processes, and are separated by a vertical fissure. Their 
greatest length is in the neck, but their greatest thickness is 
in the lumbar series. They combine great strength with re- 
markable elasticity, thus differing, in an essential particular, 
from ordinary ligaments. 

Fig. 32. 




Fig. 32. Front View of the Pelvis. — 1, 1, The inncminata. 2, The sacrum. 3, The 
coccyx. 4, 4, Socket, e, The junction of the sacrum and lower lumbar vertebra. 

92. Between every pair of true vertebrse are discoidal 
plates of white fibrous tissue, called Intervertebral Ligaments. 
These ligaments are inelastic in structure, but very elastic by 
arrangement, for the decussation of the concentric laminse 
enables them to yield to pressure and to resume their original 
position when the pressure is removed ; and this elasticity is 
greatly increased in the whole disk by the presence of a cen- 
tral pulp that occupies the hollow circle within the liga- 
mentous structure. 

93. The Pelvis is composed of the two Innomina'ta (name- 
less bones), the Sa'crum and the Coc'eyx. 



THE BONES. 43 

94. The Innominatum is the hip-bone ; in it is a deep 
socket for the head of the thigh-bone. In the centre of this 
cavity is a depression to which the round ligament of the 
thigh-bone is fixed. 

95. The Sacrum (so called because offered by the ancients 
in sacrifice) is a wedge-shaped bone, between the*4nnominata. 
In early life it is composed of five vertebrse, which become 
united in later years. It is the basis of the vertebral column. 
The texture of the sacrum is very light and spongy. 

96. The Coccyx,* at the lower extremity of the spinal 
column, varies at different ages : in infancy it is cartilaginous ; 
in adult age, formed of four pieces of bone or vertebrae ; in 
after life it becomes a continuous, blended structure. 

97. The Upper Extremities contain sixty-four bones: 
the Scap'ida (shoulder-blade) ; the Clavicle (collar-bone) ; 
the Hu'merus (arm-bone) ; the Ha! dim and JJl'na (fore-arm) ; 
the Car' pus (wrist) ; the Meta-cav'pus (palm of the hand) ; 
and the Phalan'ges (fingers and thumb.) 

98. The Scapula, a flat, thin, triagular bone, is situated 
upon the upper and back part of the chest. It lies upon 
muscles by which it is held in place and moved in different 
directions. 

99. The Clavicle, f shaped like the italic/, is attached 
at one extremity to the sternum, and at the other to the 
scapula. 

100. The Humerus is a long, cylindrical bone, joined at 
the elbow with the ulna of the fore-arm ; and at the scapular 
extremity lodged in the glenoid cavity. 

101. The Ulna J is the small bone of the fore-arm, and 
occupies the inner side. It articulates with the humerus at 
the elbow, forming a perfect hinge-joint. 

102. The Kadius§ is placed on the outside (the thumb 
side) of the fore-arm, and nearly parallel to the ulna. It is 
larger than the ulna, and articulates with it, both at the 

* From cuckoo, on account of resemblance to the cuckoo's bill. 

f Lat., clav'is, a key. % It., an ell, sl measure. § Lat., a spoke. 



44 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



elbow and at the wrist. The radius also articulates with the 
first row of bones at the wrist forming the wrist-joint. 

103. The Carpus has eight bones, arranged in two rows, 
and so firmly bound together, as to permit little movement. 
One row articulates with the fore-arm, the other with the 
metacarpus: 

Fig. 33. Fig. 34. 



,\ 



\ I 




Fig. 33. The Humerus. — 1, The shaft. 2, The large, round head that is placed in the 
glenoid cavity. 3,4, Processes for attachment of muscles. 5, A process, called the ex- 
ternal elbow. 6, A process, called the internal elbow. 7, The articulating surface upon 
which the ulna rolls. 

Fig. 34. The Fore- Arm.— 1, The ulna. 2, The radius. 3, The upper articulation of the 
radius and ulna. 4, The articulating cavity, in which the lower extremity of the 
humerus is placed. 5, The upper extremity of the ulna, called the olecranon process, 
which forms the point of the elbow. 6, Spaces between the radius and ulna, filled by the 
intervening ligament. 7, The styloid process of the ulna. 8, The surface of the radius 
and ulna, where they articulate with the bones of the wrist. 9, The styloid process of 
the radius. 

104. The Metacarpus* has five bones; upon four of 



* Gi\, meta, after or beyond, and karpos, wrist. 



THE BONES. 



45 



which, are placed the first range of finger-bones, and upon 
the other, the first thumb-bone. The metacarpal bone of the 
thumb is the shortest, and it is also disconnected with and 
divergent from the others. 

105. The Phalanges* of the fingers have -three bones, 
while the thumb has but two. The fingers are named in 
succession, the thumb, the index, the middle, the ring, and 
the little finger. 

Fig. 35. Fl «- ™. 





Fig. 35. The Wrist.— U, The ulna. R. The radius. S, The scaphoid. L, The semi- 
lunar. C, The cuneiform. P, The pisiform. The last four form the first row of carpal 
hones. T, T, The trapezium and trapezoid. M, Magnum. TJ, Unciform. The last four 
form the second row of carpal bones. 1, 1, 1, 1, Metacarpal hones. 

Fig. 36. The Hand. — 10, 10, 10, The metacarpal hones of the hand. 11, 11, First row 
of finger-bones. 12, 12, Second row of finger-bones. 13, 13, Third row of finger-bones. 
14, 15, The bones of the thumb. 

106. The Lower Extremities contain sixty bones : the 
Femur (thigh-bones) ; the Patel'la (knee-pan) ; the Tib'ia 
(shin-bone) ; the Fib'ula (small bone of the leg) ; the Tarsus 
(instep) ; the Metatarsus (middle of the foot) ; and the Pha- 
langes (toes). 

107. The Femur f is the strongest and longest bone of the 
skeleton. It supports the weight of the head, trunk and 
upper extremities. 



* Gr., row. 



f Lat., thigh. 



46 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



108. The Patella* is a small chestnut-shaped bone, 
placed on the anterior part of the lower extremity of the 
femur, and connected with the tibia by a strong ligament, 

109. The Tibia f is situated at the fore and inner part of 
the leg. It is triangular in shape. 

Fig. 37. Fig. 33. 



Fig. 37. The Femur. — 1, The shaft. 2, A projection (trochanter minor), to which are 
attached strong mnscles. 4, The trochanter major, to which are attached the large 
muscles of the hip. 3, The head of the femnr. 5, The external projection, or condyle 
of the femur. 6, The internal projection or condyle. 7, The surface of the lower ex- 
tremity of the femur, that articulates with the tibia, and upon which the patella slides. 

Fig. 38. The Bones of the Leg. — 1, The tibia. 5, The fibula. 8, The space between 
the two, filled with the interosseous ligament. 6. The articulation of the tibia and fibula 
at their upper extremity. 2, The malleolar process, or external ankle. 3, The inter-mal- 
leolar process, or internal ankle. 4, The surface of the lower extremity of the tibia, that 
unites with a tarsal bone to form the ankle-joint. 7, The upper extremity of the tibia, 
upon which the lower extremity of the femur rests. 



* Lat., little dish. 



f Lat., sl flute. 



THE BONES. 47 

110. The Fibula* is smaller than the tibia and of similar 
shape. It is firmly bound to the tibia at each extremity. 

111. The Tarsus is formed of seven irregular bones, firmly 
bound together by a few large and strong ligaments, and by 
a great number of short fibres that extend between the con- 
tiguous bones, both on the back and sole of the foot. 

11-2. The Metatarsus consists of five bones, they bear a 
close resemblance to the metacarpus of the hand. The tarsal 
an'd metatarsal bones are so united as to give the foot the 
form of a double arch. 

113. The Phalanges of the toes have fourteen bones, each 
of the small toes having three, and the great toe, two rows. 

Fig. 39. 




Fig. 39. The Upper Surface of the Bones of the Foot. — 1, The surface of the astra- 
gulus, or ankle-bone, where it unites with the tibia. 2, The body of the astragulus. 
3, Calcis, or heel-bone. 4, The scaphoid. 5, 6, 7, The cuneiform. 8, The cuboid. 9, 9, 9, 
The metatarsal bones. 10, 11, The phalanges of the great toe. 12, 13, 14, The phalanges 
of the other toes. 

114. The Joints are formed by the ends of bones, usually 
enlarged and variously united according to the purposes to 
be subserved. Generally, one surface is somewhat convex 
and the other correspondingly concave, the two parts being 
beautifully fitted to each other; associated with these, are 
the Cartilages, Ligaments, and the Synovial Membrane. 
With slight modifications, the classification of joints now 
adopted was proposed by Galen nearly two thousand years 
ago ; all the articulations being distributed into three groups — 
the Immovable (Synarthrosis) ; the Mixed (Amphiarthrosis) ; 
and the Movable (Diarthrosis). 

* Lat., a clasp. 



48 ANATOMY, PHYSIOLOGY AND HYGIENE. 

115. The Immovable Joints include the several kinds of 
suture. A suture is called Serrated when the zigzag edges 
are united as in the external plate of the skull ; Squa'mose, 
when the edges are beveled so that one overlaps the other as 
in the union of the temporal and parietal bones ; Lim'bous 
when the borders of the adjacent bones are elevated, as in 
the union of the parietal and occipital bones. Sometimes a 
false suture occurs called Harmonia, where the opposed edges 
are smooth and even, as in the internal plate of the skull, 
the upper jaw-bones, the palate, and other bones. The fitting 
of the teeth into their sockets, as a nail is driven into a board, 
is called Gomphosis:* these are improperly classed with the 
joints. 

116. The Mixed Joints are those in which the opposed 
surfaces of the bones are joined directly together by some 
intermediate soft substance, which is fibrous externally, and 
more or less cartilaginous toward its central part ; as between 
the bodies of the vertebrae, and the two upper parts of the 
sternum. 

117. The Movable Joints are the most perfect articula- 
tions, being freely movable, for which purpose, they are covered 
w r ith cartilage where the surfaces are in contact, and provided 
with synovial membrane, and connecting ligaments. They 
are of three kinds — the Planiform, the Hinge, and the Ball 
and Socket joints. The Planiform is found where the sur- 
faces of the bones are more or less plane, and the movements 
gliding, as in the articulations of the tarsus and metatarsus, 
the carpus and metacarpus ; in those of the collar-bone ; of 
the lower jaw ; of the articular processes of the cervical and 
dorsal vertebra?; of the ribs with the vertebrae, and their 
costal cartilages with the sternum ; and of the tibia with the 
fibula : The Hinge joint (Ginglyform), where there is motion 
in two directions only, backward and forward, as at the knee 
and the elbow ; the ankle and the wrist ; and the joints of the 
phalanges of the fingers, and the toes. In this joint, the end 

* Gr., gomphos, a nail. 



THE BONES. 49 

of one bone is so modeled as to present a median groove, and 
two lateral projections ; while the end of the other has a 
median projection, and two lateral grooves : The Ball and 
Socket joint (Enarthrosis), also called Rotary, where there is 
free movement in all directions ; it consists of a cup-like 
cavity in one bone, and a rounded extremity to fit it, in the 
other, bone, as seen in the hip and shoulder joints ; the 
socket at the hip is called the Acetabulum;* at the shoulder, 
the- Glenoid cavity. 

118. There are certain forms of movable joints which re- 
quire special description. The articulation between the upper 
ends of the radius and ulna, may be called a ring or collar 
joint ; for the convex head of the radius plays into a very 
shallow cavity of the ulna, and is bound to it by a ring of 
ligament passing around the head of the radius. At the 
wrist, by a similar arrangement, the head of the ulna plays 
into the radius. The joint permitting the rotary motion of 
the head, is somewhat similar; a tooth-like projection of the 
axis playing into the anterior part of the ring of the atlas is 
held in position by transverse ligaments crossing behind it. 
The articulation allowing the nodding motion of the head, 
really consists of two separate joints, one on each side of the 
median plane ; these joints are between the lower skull-bone 
and the atlas. 

$ 8. Histology of the Bones. — Formation of Temporary Cartilage. 
Intra- Cartilaginous Mode of Bone- Formation. — Intra- Membranous 
Mode. Periosteum. Endosteum. Cartilages of the Joints. Synovial 
Membrane. Ligaments. 

119. The primitive basis, or plasma of the bone, is a sub- 
transparent, glairy matter containing numberless minute 
corpuscles. It gradually acquires firmness, and nucleated 
cells appear, indicating the change into cartilage. As these 
cells increase in number and size, they become aggregated in 
rows, or columns, with intercellular tracts where ossification 

* Lat., acetum, vinegar, from resemblance to the vinegar-cup of the 
ancients. 

5 C 



50 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



is about to begin. In the cartilaginous basis of long bones, 
these rows are vertical to the ends; in that of flat bones, to 
the margin, 

120. The first appearance of bone is that of minute granules 
in the intercellular tracts. Afterward, the cartilage corpuscles 
become filled with these granules in all parts excepting their 
nuclei, which remain isolated in the bony substance. From 
these proceed minute canals, which become enlarged, forming 
the cavities called Lacunce. These everywhere connect with 
each other by minute tubes, called Canalic'idi. One layer 



Fig. 40. 



Fig. 41. 





Fig. 40 (Leidy). An Osseous Lacuna, exhibiting its numerous diverging canaliculi; 
highly magnified. 
Fig. 41 (Lessing). Haversian Canal, lacuna? and connecting canaliculi. 

of cells after another is thus converted into bony plates, till 
the whole column is filled excepting a fine central tube called 
the Canal of Havers. This microscopic, osseous cylinder is 
called an ossicle, and is a true miniature of any one of the 
long bones. The compact portion of all bones is made up of 
these ossicles, which, under the microscope, resemble bundles 
of pipe-stems, placed side by side ; the interspaces being filled 
with lamellated bone-substance. This mode of bone-forma- 
tion, is called Intra-cartilaginous. 

121. There is another mode of bone-development widely 
distributed through the body, called Intra-membranous ; as 
seen in the flat bones. The membrane in which this ossifica- 



THE BONES. 



51 



tion takes place seems to consist of soft, amorphous matter, 
containing granular corpuscles. From certain points, called 
centres of ossification, the growing bone shoots into the soft 
substance in the form of transparent fibres which gradually 
become charged with earthy salts. The number of these 
centres varies in different bones — the parietal having one ; 
the frontal, two ; the occipital, four ; and others, still more. 
It is supposed that the corpuscles become the lacunae of the 
borie. By the fibres radiating from the centres of ossifica- 
tion, little grooves are formed which become the canals of 
Havers. The lacunae connect with each other and with the 
Haversian canals ; thus establishing a free communication 
between all parts of the bone. 



Fig. 42. 




Fig. 42 (Leidy). Transverse Section of Bone from the Shaft of the Femur; 
highly magnified. The large circular orifices are transverse sections of the Havers 
canals, surrounded by concentric layers of osseous substance. Between the latter are 
seen the lenticular excavations or lacuna^ intercommunicating by means of canaliculi. 



52 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



122. The long bones are hollow cylinders compact upon 
the exterior, and cancellated, or spongy within. This open 
texture increases toward the ends, which it entirely fills ex- 
cepting the very thin, hard wall. The cylindrical cavity is 
filled with a yellowish fat called Medid'la, consisting of soft, 
delicate adipose cells. 

Fig. 43. 





Fig. 43 (Leidy). Longitudinal Section of the Proximal Extremity of the Femur, 
exhibiting the arrangement of the spongy substance. 1, 2, Positions in which the com- 
pact substance appears to resolve itself into a series of arches. 

Fig. 44. A Tjrtical Section of the Kxee-Joint.— 1, The femur. 3, The patella. 
6, The tibia. 2, 4, Ligaments of the patella. 6, Cartilage of the tibia. 12, The cartilage 
of the femur. * * fc * The synovial membrane. 

123. With the exception of the cartilage-tipped extremities, 
the bones are invested with a dense, white-fibrous membrane, 
called Peri 'osteum ;* and even at the joints it may be traced 
over the capsular ligaments, thus realizing the opinion of the 
ancients that the periosteum formed a complete sac for the 
whole skeleton. Nor is this true of the external only ; for, 
continuous with the periosteum, and lining the medullary 
cavity and various openings of the bone, there is a web-like 



Lat., peri, around, and os, a bone. 



THE BONES. 53 

and very vascular membrane of extreme tenuity, called En- 
dosteum,* or Internal Periosteum. 

124. In order to facilitate the movements of bones upon 
each other, they are covered at the joints, with a thinnish 
layer of Cartilage or gristle — a tough, elastic, pearly-white 
substance, very smooth on the free surface (25). Upon con- 
vex surfaces, it is thickest in the centre, while upon concave 
surfaces, it is thickest toward the circumference. This car- 
tilage is sometimes interposed as a ring, forming a movable 
socket, which, like the friction-wheels of machinery, aids the 
motion of the joint. This arrangement is seen in the lower 
jaw, the cartilage being attached to the synovial membrane, 
but perfectly movable and following the movements of the 
jaw, thus preventing dislocation. 

125. The Synovial Membrane (40) secretes a viscid 
fluid, called Syn'ovia, which lubricates the movable joints. 
This membrane is of three kinds; — the Articular Capsules, 
the Bursce Mucosas, and the Sub-cutaneous Synovial Capsules. 
The Articular Capsule forms a complete sac, which covers the 
articular surface of one bone, and is thence reflected to the 
other, adhering closely to the borders of each of the car- 
tilaginous surfaces. The Bursce Mucosae are pouches of syno- 
vial membrane interposed between bones and the tendons 
that play upon them like cords upon pulleys ; they also occur 
where tendons or muscles move upon ligaments, fibro-car- 
tilages, or upon each other. Tendons moving through grooves 
of bone are enclosed in a synovial tube which is reflected 
upon itself so as to line the groove within which the motion 
takes place. The Sub-cutaneous Capsule, or membrane, is 
found wherever the skin is frequently moved over a resisting 
part, as between the skin and patella at the knee. Wherever 
a number of tendons move upon one another, this membrane 
is folded around and among them ; it appears to have the 
same function as the bursse mucosa?. 

126. Outside the synovial membrane, and more or less 

* Gr., within, and os, bone. 
5* 



54 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



connected with it, are the special ties of the joints, called 
Ligaments. These ligaments are composed of white-fibrous 
tissue and are named Cap'sular, Band-like, and Funicular. 
The Capsular Ligaments are cylindrical sacs, extending com- 
pletely around the joints, and blending with the periosteum. 
This form is found with the ball-and-socket joint. The hip 
and the shoulder joints furnish perfect examples of the liga- 
mentous capsule. The Band-like Ligaments are broad bands 
of parallel fibres, found with the hinge-joint; and sometimes, 
where great strength is needed, as accessory to the capsular 
ligament. The Funicular Ligaments are cords round or flat, 
which extend from one bone to another, sometimes within 
and sometimes without the joint. An example is seen in the 
two ligaments crossing each other within the knee-joint, also 
in the single ligament within and connecting the ball-and- 
socket joint of the hip. 



Fig. 45. 



Fig. 46. 





Fig. 45 (Leidy). The Right Knee- Joint, laid open from the front. 1, Articular sur- 
face of the femur. 2, 3, Crucial ligaments. 4, Insertion of one of these ligaments into 
the tibia. 6, 7, Internal and external semi-lunar fibro-cartilages. 8, Ligament of the 
patella turned down, so as to exhibit the synovial bursa (9) beneath. 10, Superior tibio- 
fibular articulation. 11, Interosseous membrane. 

Fig. 46 (Leidy). Front Yiew of the Right Knee-Joint. — 1, Tendon of the quadri- 
ceps extensor muscle. 2, Patella. 3, Ligament of the patella, or tendinous insertion of 
the muscle just mentioned. 4, 4, Capsular ligament. 5, 6, Internal and external lateral 
ligaments. 7, Superior tibio-fibular articulation. 



THE BONES. 55 

§ 9. Chemistry of the Boxes. — Chemical Composition of the Bones. 
— Experiments showing Earthy and Animal Matter. 

127 '. Bones are composed of both animal and mineral mat- 
ter ; the animal matter being in excess in early life, and the 
mineral, in old age. The average proportion is about thirty- 
three per cent, animal matter (cartilage and blood-vessels) ; 
and sixty-seven per cent, mineral, of which fifty-one parts are 
bone-earth (phosphate of lime) ; eleven parts chalk (carbonate 
of lime) ; the remaining parts are fluor spar (fluoride of cal- 
cium) ; phosphate of magnesia; and common salt (chloride of 
sodium). 

Observation. — To show the earthy without the animal mat- 
ter, burn a bone in a clear fire, and it becomes white and 
brittle, the animal part having been consumed. To show 
the animal without the earthy matter, immerse a slender 
bone, for a few days, in weak acid (one part muriatic acid 
and six parts water) and it becomes flexible, the earthy mat- 
ter having been removed. 

\ 10. Physiology of the Bones.— General Uses of the Bones. — 

Adaptation of their Structure to their Uses. Skill as shown in the 
Skull. — In the Spinal Column. — In the Bibs. — In the Pelvis. — In the 
Upper Extremities. — In the Lower Extremities. — In the Long Bones. 
The uses of the Joints. Classification of the Joints. — Of Movable Joints. 
Function of the Synovia. Of the Cartilages. Of the Ligaments. Of 
the Periosteum. Perfection of this part of the Animal Fabric. 

128. The Boxes serve as the framework of the system ; 
as bases for the attachment of muscles ; as levers for the 
organs of locomotion ; as pulleys for the passage of tendons ; 
and as protection for the delicate internal organs. In their 
adaptation to their several offices, they exhibit a perfection 
of mechanism worthy the infinite mind of the Divine 
Architect. 

129. In the minutest structure of the bones as revealed by 
the microscope, we find the delicate tissues so disposed as to 
give the greatest amount of strength and lightness, and a 
certain degree of elasticity— qualities essential to the per- 



56 

form an ce of their several offices. In their more general 
structure, we see regard to the same qualities, the exterior 
being dense and compact, the interior, spongy, or cancellated. 
Take any bone, or series of bones, and note their peculiar 
configurations and the purposes to be subserved, and there 
appears the same marked evidence of special care and skill- 
ful mechanism. 

130. In the arrangement of the Skull for the protection 
of the brain, the oval form (the form best adapted to resist 
pressure equally applied on all sides) ; the thickened base 
where the most important part of the brain lies ; the strong 
and narrow prominences, both in front and back, where most 
exposed to violence ; the tough and hard plates to resist the 
penetration of sharp substances ; the intervening spongy layer 
to diminish vibrations ; the separate bones, and the serrated 
unions of the external plates, also to lessen shocks ; the simple 
contact of plane edges in the internal vitreous plate, where 
zigzag edges would be easily broken ; the projections, de- 
pressions, and apertures for the safe passage of nerves and 
blood-vessels — all combine to accomplish the one object, 
protection. 

131. To construct the Spinal Column was no easy me- 
chanical problem. These offices were to be taken into the 
account : 1. It must support the head ; 2, furnish an axis of 
support for the other parts of the body ; 3, allow a bending 
and somewhat rotary movement; 4, furnish a basis for the 
attachment of muscles ; 5, provide passages and protection 
for the spinal cord and nerves ; 6, the whole must be arranged 
with reference to the importance and delicacy of the brain. 

132. To furnish proper support, it must possess firmness 
and strength ; these are secured by the broad bases of the 
vertebrae, which increase in size according to the increase of 
weight to be supported, by the powerful ligaments extend- 
ing the length of the column, and by the interlocking of the 
projections of the vertebrae: To secure the necessary rotary 
movement, there are short horizontal processes in the cervical 
and lumbar regions, while those of the dorsal vertebrae, where 



THE BONES. 57 

movement is not required, are long and extend downward ; 
flexibility and firmness are two qualities difficult to unite, 
but here the union is effected by making the vertebrae of 
short bones and increasing their number, and by the me- 
chanical arrangement of the fibres of the disks between the 
vertebrae: To furnish an attachment for muscles, are the 
dense processes, which vary in size, form, and direction, ac- 
cording to the requirements of the muscles to be attached : 
To provide for the spinal cord, each vertebra has a perfora- 
tion, and these openings, coming directly over each other, 
form a bony canal, while at the sides of this canal, are 
apertures for the passage of nerves ; the spinal cord is still 
farther protected by the elastic ligaments between the arches 
of the vertebrae, allowing no openings in the bending of the 
body; and by the number of the vertebrae, for were there 
only three or four bones, the cord would be injured at every 
angle : The number of vertebrae, the cartilage cushions, and 
the four curves of the column, all tend to secure the brain 
from shocks it would otherwise receive, from walking, leap- 
ing, and running. 

133. The Ribs serve to protect the delicate organs of the 
chest. These slender bones should be elastic and movable : 
The first quality is secured by the cartilaginous union to the 
sternum ; the second, by their cartilages, their articulations 
with the spine, and their oblique position. 

134. The Pelvis not only furnishes support for the upper 
part of the body, and the articulations of the lower extremi- 
ties, but also serves as a base for the attachment of the power- 
ful erector muscles of the spine, the muscles for moving the 
lower limbs, and the muscles which shut in the abdominal 
and pelvic cavities. 

135. The form and proportion of the Upper Extremities 
relate to the hand, which belongs exclusively to man, and gives 
the power of execution to the human mind : Thus, the arm is 
longer than the fore-arm, and this, longer than the hand, 
securing greater mobility, flexibility, and power of adaptation 
as we approach this delicate organ of prehension. It is the 

c* 



58 ANATOMY, PHYSIOLOGY AND HYGIENE. 

relative position of the four fingers to the thumb, however, 
which principally stamps the character of the hand, as this 
construction permits its adaptation to every shape, and gives 
that complete dominion which it possesses over the various 
forms of matter. 

136. The Lower Extremities have a strong analogy to 
the upper, the differences being only such as are necessary to 
constitute them organs of locomotion rather than of prehen- 
sion ; hence, their solidity, at the expense of their mobility. 
The tarsal and metatarsal bones form a strong arch toward 
the inner and lower surface of the foot, protecting the vessels, 
nerves, and tendons, passing from the leg to the foot, and the 
opposite. 

Fig. 47. 




Fig. 47. A Side View of the Bones of the Foot, showing its Arched Form. — The 
arch rests upon the heel behind, and the hall of the toes in front. 1, The lower part of 
the tibia. 2, 3, 4, 5, Bones of the tarsus. 6, The metatarsal bone. 7, 8, The bones of the 
great toe. 

137. The shafts of long bones are made hollow, giving not 
only lightness but strength, according to the well-known prin- 
ciple in mechanics, that, with a given amount of material, a 
hollow cylinder will sustain more weight than a solid one, 
both being of the same height : (The same principle is illus- 
trated in the culms of grasses.) We find the walls most 
compact, and the cavity broadest at the middle of the cylin- 
der, the part subjected to the greatest strain ; we find the ex- 
tremities enlarged, to give a broader surface for the attach- 
ment of muscles, and often to change the direction in the 



THE BONES. 59 

action of muscular power; also more spongy in texture, to 
increase the size without corresponding increase of weight. 

138. The Joints. The uses of the joints are to enable the 
body to sustain greater weight (as several short pillars will 
support more weight than a single pillar of the same height 
and thickness) ; to diminish the force of blows or shocks ; to 
afford freedom of movement; to provide fulcrums for the 
various levers ; to modify the direction in the action of mus- 
cular power, and to determine the plane of action. 

139. For simple union without movement, we find the 
Immovable joint ; for great strength and little movement, 
the Mixed joint; and for full freedom of movement, the 
Movable joint. Of the movable joints for motion in one 
plane and two directions, we find the Hinge-joint; for the 
gliding movement, the Planiform joint ; and for free rotary 
motion, the Ball-and-Socket joint. At the hip, the socket is 
very deep, giving strength ; at the shoulder, it is shallow, 
giving unrestricted motion; everywhere the configuration 
and the use correspond. 

140. The use of the Synovia is to enable the surfaces of the 
bones to move more easily upon each other, preventing fric- 
tion and consequent wear. No machine of human invention 
manufactures for itself the necessary lubricating fluid, but, 
in the animal mechanism, it is supplied in proper quantities, 
applied in the proper places, and at the proper time. 

141. Cartilage tips the articular extremities of bones, 
facilitating the sliding motion, and deadening shocks ; and in 
various parts of the body it serves as an elastic cushion, 
yielding on compression and regaining its form when the 
pressure is removed. 

142. The function of the Ligaments is to bind together 
the bones of the system. By them the lower jaw is bound to 
the temporal bones, and the head to the neck ; they extend 
the length of the spinal column, between the vertebrae, and 
from one spinous process to another ; they bind the ribs to 
the vertebrae, and the sternum ; the sternum to the clavicle ; 
the clavicle to the first rib and the scapula ; the scapula to 



60 ANATOMY, PHYSIOLOGY AND HYGIENE. 

the humerus ; the bones of the fore-arm at the elbow-joint 
and also at the wrist ; the bones of the wrist to each other, 
and to those of the hand ; and these to each other, and to 
those of the fingers and thumb : In the same manner they 
bind the bones of the pelvis together ; and these to the femur, 
or thigh-bone ; and this to the two bones of the leg and the 
patella, or knee-pan ; and so on to the ankle, foot and toes, as 
in the upper extremities. The bones of the wrist and those 
of the foot are as firmly fastened as if bound by clasps of 
steel. 

143. The Periosteum serves to transmit blood-vessels into 
the bone, thus furnishing nutriment; it gives insertion to 
muscles, tendons and ligaments; obviates the effects of fric- 
tion ; strengthens the whole skeleton as an investing mem- 
brane, and possesses some agency in the process of ossifi- 
cation. 

144. We have noticed but a few of the many wonderful 
examples of skill, wisdom and benevolence exhibited in the 
internal framework of the animal fabric. Each bone, how- 
ever small, illustrates some profound principle of science; 
each is perfect in its adaptation to a specific use. The whole 
structure is a faultless piece of mechanism, in which every 
known principle of architecture and dynamics has been 
brought into service. 

§ 11. Hygiene of the Bones. — Effect of Exercise upon the Bones of 
Children. — Effect of Compression. — Of Stooping. Treatment of Frac- 
tures. — Of Sprains. — Of Felons. 

145. The health of the bones is 'promoted by regular exercise. 
The kind and amount of labor, should be adapted to the age, 
health, and development of the bones ; neither the cartilaginous 
bones of the child, nor the brittle bones of the aged man, are 
adapted to long-continued and severe exercise. While pro- 
tracted exercise in childhood is injurious, moderate and regu- 
lar labor favors a healthy development and consolidation of 
the bones. In middle age, the proportions of animal and 
earthy matter are usually such as to give the proper degree 



THE BOXES. 



61 



of flexibility, firmness and strength, with little liability to 
injury. 

146. The lower extremities of the very young, are not adapted 
to sustaining much weight; hence, to induce a child to walk, 
or to stand by chairs, while the bones of the lower limbs are 
imperfectly developed, is ill-advised and productive of serious 
injury. The "bandy" or "bow" legs are thus produced. 
The benches or chairs for children in a school-room, should 
permit the feet to rest upon the floor, otherwise the weight of 
the limbs, below the knee, may cause the flexible bone of the 
thigh to become curved ; the chairs should also have suitable 
backs, and the child be allowed frequent change of position. 



Fig. 48. 



Fig. 49. 




Fig. 48. Natural Position when the feet are supported. 
Fig. 49. Unnatural Position when a seat is too high. 



147. Compression of the chest should be avoided. In youth, 
the ribs are very flexible, and a small amount of pressure 
will increase their curvature, particularly at the lower part 
of the waist. By tight or "snug" clothing the ribs are drawn 
down, and the space between them lessened, so that in some 



62 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



instances, the anterior extremities of the lower ribs are brought 
quite together ; hence, the apparel should be loose and sup- 
ported by the shoulders, both for children and adults. 

148. An erect position both in sitting and standing should be 
carefully maintained. The spinal column naturally curves 
from front to back, but not from side to side. The admirable 
arrangement of the bones and cartilages permits a great variety 
of motions and positions, the elasticity of the cartilages always 
tending to restore the spine to its natural position ; but if a 
stooping, or a lateral curved posture be continued for a long 
time, the compressed edges of the cartilages lose their power 
of reaction, and finally, one side becomes thinned, while the 
other is thickened. These wedge-shaped cartilages produce 
permanent curvature of the spine, which is often attended 
with disease of the spinal cord. 



Fig. 50. 



Fig. 51. 





Fig. 50. A Chest well proportioned. 
Fig. 51. A Chest fashionably deformed. 



149. The student, seamstress, and artisan, frequently ac- 
quire a stooping position, by inclining forward to bring their 
books or work nearer the eyes. The desk of the pupil is 



THE BONES. 63 

often higher than the elbow as it hangs from the shoulder at 
rest, consequently, in drawing, writing, and often in studying, 
one shoulder is elevated and the other depressed, distorting 
the spine. In the daily employments of life, children should 
early be taught to use the left hand and shoulder more freely. 
Distortions of the chest necessarily accompany deformity of 
the spine, and disease of the heart and lungs follows, compared 
to which, the loss of symmetry is a minor consideration. 

Fig. 52. 




Fig. 52. A Deformed Thorax and Spinal Column. 

150. Eminent physicians, both in this country and Europe, 
state that, among the fashionably educated, not one female in 
ten escapes deformities of the shoulders and spinal column. 
The student, to prevent as well as to cure slight curvatures 
of the spine, should walk with a book, or a heavier weight 
upon the head. Porters and laborers of some countries, bear 
very great burdens upon their heads, and walk at a rapid 
pace with comparative ease. Itinerant toymen carry securely 



64 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



their trays of fragile merchandise, because the head and 
spinal column are erect. 



Fig. 53. 




Fig. 53. Correct Position in Sitting.— 1, 1, The spinal column straight ; the shoul- 
ders of equal height. 

151. Fractured or diseased bones and ligaments should re- 
ceive special attention. In fractured bones, a surgeon's care is 
not only needed to adjust the parts, but for several weeks, to 
watch the reunion, that the limb may not be crooked or 
shortened. In sprains, the ligaments are not usually lacerated, 
but strained and twisted, causing much pain, and afterward 
inflammation and weakness of the joints. To effect a cure, 
there should be absolute rest for days, and perhaps weeks. 
More persons are crippled from ill-cared-for sprains, than 
fractured bones. Persons enfeebled by disease, particularly 
scrofula, cannot be too assiduous, in adopting an early and 



THE BONES. 



65 



proper treatment of injured joints, to prevent the affection, 
called " white swelling." 

Observation. — The disease called "Felon" is an inflamma- 
tion that commences in or beneath the periosteum. It is 
attended with severe, throbbing pain, and the unyielding 
structure of the parts prevents much swelling. The only 
successful treatment of this painful affection, is an early, free 
opening through the periosteum to the surface of the bone. 
The earlier the incision is made, the less the risk and the 
suffering. 

Fig. 54. 




Fig. 54. Incorrect Position in Sitting. — 1, 1, Three curves of the spine ; the shoul« 
ders of unequal height. 

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66 



ANATOMY, PHYSIOLOGY AND HYGIEXE. 



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THE BONES. 67 

\ 13. Comparative Osteology. — Classification of Animals according 
to their Plan of Structure. Classification of Vertebrates. Compare 
Spinal Columns of Vertebrates. — Bones of the Head. — Of the Thorax. — 
Of the Extremities. 

152. The tissues, cells, and chemical composition of all 
animals are essentially the same, but their different appoint- 
ments in the plan of creation require special conformations. 
Animals have therefore been arranged, according to their 
plan of structure, into four sub-kingdoms : — 1. Vertebrata, 
including man and other animals having an internal skeleton 
with a back-bone as its basis, the bones being composed chiefly 
of phosphate of lime : 2. Articulata, comprising animals 
having an external skeleton made up of similar segments, or 
rings, consisting mostly of the carbonate of lime; as insects, 
lobsters and worms : 3. Mollusca, including soft-bodied ani- 
mals covered w 7 ith a hard shell consisting of one or two pieces, 
also composed of carbonate of lime ; as cuttlefish, oysters, 
clams, and snails : 4. Eadiata, having no proper skeleton or 
shell-covering, but parts more or less symmetrically arranged 
about a vertical axis ; as star-fishes, sea-anemones and coral 
animals. 

153. The Vertebrata are classified as Mammals (including 
man, monkeys, bats, quadrupeds, etc.), Birds, Reptiles and 
Fishes. 

154. The Vertebral Column of all Mammals is similar 
to that of man. The cervical vertebrae, with two exceptions, 
number seven : the dorsal, average thirteen ; the lumbar, 
from three to seven; the, sacral, usually four; the caudal, 
from four (the number of the coccyx in man) to forty-six. 
The length of any part of the column seems to depend not so 
much upon the number of the vertebrae as upon their length ; 
thus we find seven cervical vertebrae in the long-necked giraffe 
and in the short-necked mole. In Birds, the flexibility of the 
neck enables any part of the body to be reached by the beak. 
This is owing to the ball-and-socket articulations, and to the 
great number of cervical vertebrae, which in the swan are 
twenty-four ; in the ostrich, eighteen ; and in the domestic 



f 



68 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



cock, thirteen. The dorsal vertebrae vary from seven to 
eleven, and are generally consolidated into one; but in birds 
that do not fly, they remain distinct and movable. The 
lumbar and sacral vertebrae are united into one. The last 
caudal vertebra has a large, strong process for the support 
of the large feathers. In Reptiles, the vertebrae vary in num- 
ber from some twenty-four, as in the frog, to four hundred, as 
in some snakes, as the Python. Perhaps about one hundred 
is the average number. In Fishes there are but two kinds of 
vertebrae, the dorsal and the caudal, and these vary in num- 
ber from twenty to two hundred. The vertebral bodies pre- 
sent a conical, cup-like depression on each side, which contains 
a gelatinous fluid having the same use as the elastic inter- 
vertebral substances in mammals. 

Fig. 56. 




Fig. 56. Skeleton of a Bird.— 1, The head. 2, Cervical vertebrae. 3, Dorsal and lum- 
bar vertebrse. 4, Scapula. 5, Clavicle. 6, Coracoid bone. 7, Sternum. 8, Humerus. 
9, Radius. 10, Ulna. 11, Carpus. 12, Metacarpus. 13, 13, Phalanges (fingers). 14, 
Femur. 15, Tibia. 16, Fibula. 17, Tarsus. 18, Metatarsus. 19, Phalanges (toes). 



THE BONES. 69 

155. The Bones of the Head of all the Mammals re- 
semble, in many points, those of man. In some quadrupeds, 
as the horse and the cow, the frontal bone is in two parts ; in 
others, the two parietal bones are united : Between the two 
upper maxillary bones, are two small bones called inter- 
maxillary; the lower jaw consists of two pieces. In Birds, 
the -bones of the head, in number and position, resemble 
mammals, but they are early united, leaving no trace of the 
sutures. The superior mandible, or upper jaw, of the bird is 
so articulated with the cranium as to admit of motion inde- 
pendent of the lower jaw (which never occurs in mammals), 
and the inferior mandible, instead of being articulated directly 
with the cranium, is connected through the intermedium of 
a distinct bone called the Os Quadratum. In Reptiles the 
head-bones are irregular in form, and greatly vary in num- 
ber. In Fishes the bones of the head are numerous and 
irregular, and their study is a matter of much interest in 
acquiring a full knowledge of Natural History. 

156. The obvious use of the Clavicle is to maintain the 
shoulders apart; hence in quadrupeds, where its presence 
would be a defect, it is wanting, as in the horse and cow. 
The clavicles of Birds are peculiar; they unite at their ante- 
rior extremity, forming a forked bone called furcula, or wish- 
bone. In birds of powerful flight, as the eagle, the clavicles 
are very strong ; in others, as the domestic turkey, they are 
weak. Connecting the scapula to the sternum is the eor'aeoid 
bone, which is placed side by side with the furcula, and is 
the main source of support to the wings in flight. In some 
Reptiles, as the tortoise, both the clavicle and the coracoid 
bone are found, while in others, as serpents, both are want- 
ing. In Fishes the true clavicle is wanting, but in some 
species there is a modified form of the coracoid bone, free at 
its lower extremities, which may, perhaps, be considered as 
homologous with the coracoid bone or clavicle of the higher 
animals. 

157. The Scapula is present in all Mammals and Birds, 
and most Reptiles and Fishes. 



70 ANATOMY, PHYSIOLOGY AND HYGIENE. 

Fig. 57. 




Fig. 57. Skeleton of a Tortoise.— 1, Cervical, 2, Dorsal, 3, Lumbar vertebras. 4, 
Scapula. 5, Clavicle. 6, Coracoid bone. 13, Humerus. 14, Ulna. 15, Radius. 16, 
Carpus. 17, Phalanges (fingers). 7, Femur. 8, Tibia. 9, Fibula. 10, Tarsus. 11, Meta- 
tarsus. 12, Phalanges (toes). 

158. The Sternum of birds is the largest bone in their 
bodies. It has upon its anterior surface a ridge resembling 
the keel of a ship, for the support of the pectoral muscles 
used in flying. The size is proportioned to the powers of 
flight; hence in the little humming-bird, which is on the 
wing most of the day, it reaches the maximum of develop- 
ment. Of the Reptiles, serpents have no sternum ; but in 
turtles, it has an extraordinary development, and extends 
from the base of the neck to the commencement of the tail, 
forming the ventral part of the shell-covering. In some 
Fishes, the sternum is represented by a chain of bones. 



THE BONES. 



71 



159. The Ribs are much alike in all Mammals. In Birds, 
the cartilage that unites the rib to the sternum is osseous, 
giving solidity to the chest. In some Reptiles, as lizards, 
crocodiles, and other reptiles formed in the same way, the 
ribs are more numerous than in mammals and birds, and 
protect the abdomen as well as the chest. In the turtle, the 
ribs are expanded, forming the dorsal part of its shell, or the 
roof of its portable dwelling-house. In serpents, the lower 
or 'anterior extremities of the ribs have no cartilage : they 
aid in progressive movement, or crawling, as, under the skin, 
their ends can be placed on the ground like feet. In some 
Fishes, the ribs are wanting ; in others, they are very com- 
plete and surround the trunk ; in still others, they are con- 
nected with a chain of bones representing the sternum. 

Fig. 58. 




Eig. 58. The Skeleton of a Haddock. 



160. The Humerus is usually a long, hollow bone, with a 
rounded head at the upper extremity, but in animals that 
swim or burrow, it is short and flattened at the ends for the 
attachment of muscles, thus enabling the fore-limbs to be 
used with much force. In Birds, the humerus is larger than 
the femur, contrary to the relative proportion in man. 

161. The Radius and Ulna are present in most Mammals, 
but they are incapable of moving upon each other. In Birds, 
they are longer in proportion than in Mammals, especially in 
birds of flight. 



72 ANATOMY, PHYSIOLOGY AND HYGIENE. 

162. The Carpus of Mammals is made up of two rows, but 
the number of bones varies from five to eleven. In Birds, it 
is represented by two short bones. The Metacarpus usually 
consists of five elongated bones, but, in the horse, only one 
bone with two rudimentary ones are found. Most mammals 
have five fingers, of which the thumb is generally rudi- 
mentary. In some Birds, the thumb is entirely wanting, also 
the little finger. The middle finger is longest, consisting of 
two and even three bones. 

163. The Posterior Extremities of quadrupeds are 
usually less modified than the anterior. In Birds, the 
Femur is short ; the Tibia is the chief or longest bone of the 
hind limb ; the Fibula is a small bone united at various dis- 
tances down the tibia in different birds. A single bone re- 
presents the Tarsus and Metatarsus ; this supports or carries 
the toes, which in birds never exceed four in number. In 
some Reptiles, as the tortoise, lizard and others, the anterior 
and posterior limbs are composed of bones which, in number, 
form, position and functions, much resemble the correspond- 
ing ones in mammals and birds : in the serpent tribe, the 
limbs are wanting. In Fishes the extremities are rudi- 
mentary, being represented by fins. 

Suggestion. — The osteology of the three lower sub-kingdoms 
of animals is replete with interest and instruction, but the 
necessarily limited space of this elementary school-book en- 
tirely precludes their consideration : allow us to advise all 
who can command the leisure, to extend this study to the 
beautiful and wonderful works of creation as seen in these 
parts of the garden of the Lord. 



CHAPTEK V. 

THE MUSCLES. 

I 13. Anatomy of the Muscles. — Law of Muscular Contraction. — 
Consequent Forms of Muscles. Modes of Attachment of Muscles. — 
Number and General Arrangement. Muscles of the Head and Neck. — 
Of the Upper Extremities. — Of the Trunk. — Of the Lower Extremities. 

164. The Characteristic Property of muscles is con- 
tractility, and the law is, that they shall contract toward the 
centre. To accomplish this, there must be diversity of form, 
adapting them to different positions ; hence, muscular fibres 
are longitudinal, terminating at each extremity in a tendon, 
forming a spindle-shaped or fusiform muscle; disposed like 
the rays of a fan, converging to a tendinous point, a radiate 
muscle; converging to one side of a tendon running the whole 
length of a muscle, as one side of the plume of a feather to 
its shaft, a penniform muscle; converging to both sides of the 
tendon like an entire feather, a bi-penniform muscle; or run- 
ning in a circular direction, an orbicular, or sphincter muscle. 

Fig. 59. 




12 3 4 

Fig. 59. 1, A Representation of the Direction and Arrangement of the Fibres 
in a fusiform or spindle-shaped muscle. 2, In a radiated muscle. 3, In a penniform 
muscle. 4, In a bi-penniform muscle, t, t, The tendons of a muscle. 

7 B 73 



74 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



165. Muscles are usually attached by both their extremities 
to the bones, either directly, or indirectly by means of the 
inelastic but flexible tendons, which may be cord-like (either 
round or flattened) or flat and broad, supporting the organs 
which they surround, and named Aponeuroses, or Fascice. 
Sometimes the muscle is attached to bone by one extremity 
only, the other being fixed to the skin or other soft part, as 
certain of the muscles of the face : sometimes there is no 
connection with bone, as in the orbicular muscle of the 
mouth. When a muscle is attached to bone by one extremity 
only, that attachment is called its origin, the other being 
termed its insertion; when attached at both ends to the bones, 
the attachment nearer the centre of the body, and which is 
usually the more fixed point, is called the origin, while that 
more distant and movable is named the insertion. Muscles 
may have one, two, three, or many points of origin, and some 
muscles have more than one point of insertion. 

Fig. 60. 




Fig. 60. A Transverse Section of the Nkck. — The separate muscles, as they are 
arranged in layers, with their investing fascia?, are well represented. 12, The trachea. 
13, The oesophagus. 14, Carotid artery and jugular vein. 28, One of the bones of the 
spinal column. (The figures in the white spaces represent fascia ; other figures, muscles ; 
as the system is symmetrical, figures are placed only on one side.) 

166. The number of muscles in the human body is more 



THE MUSCLES. 75 

than five hundred, In general, they form about the skeleton 
two layers, distinguished as superficial, and deep-seated muscles ; 
yet in some parts there are three, four, five, and even six 
layers. 

167. With the exception of twelve single muscles, they are 
arranged in pairs. Each muscle has its antagonist; when 
one contracts, the other relaxes. The muscles passing over 
the back of a joint are usually called Extensors, because they 
serve to extend the part beyond the joint; while those lying 
in front of the joint are, for the opposite reason, called 
Flexors. 

Examples. — 1st, Clasp the arm midway between the shoul- 
der and elbow, with the thumb and fingers of the opposite 
hand ; when the arm is bent, the inside muscle is hard and 
prominent, and the tendon near the elbow, rigid, while that 
upon the opposite side is relaxed : straighten the arm, and 
the outside muscle swells and becomes firm, while the inside 
muscle and its tendon are relaxed. 

2d, Clasp the fore-arm about three inches below the elbow, 
then open and shut the fingers rapidly, and the alternate 
contraction and relaxation of the muscles on the opposite 
sides of the arm are felt, the movements corresponding to 
those of the fingers: when the fingers bend, the inside 
muscles contract, and the outside ones relax ; when the 
fingers open, the inside muscles relax, and the outside con- 
tract. This action of antagonist muscles may be felt in all 
the different movements of the limbs. 

MUSCLES OF THE HEAD AND NECK. 

168. The Occipito-Frontalis elevates the eyebrows. 
The Orbicularis Palpebrarum closes the eyelids, and, 

by pressing back the ball of the eye, it also compresses the 
lachrymal gland and causes a flow of tears. 

The Orbicularis Oris closes the mouth, and enables the 
lips to embrace any substance placed between them. It re- 
ceives into its periphery the fibres of the surrounding muscles, 
which meet here as in a common centre. It enters largely 



76 ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 61 




THE MUSCLES. 77 

into the diversified expressions of the countenance, and in no 
one respect exhibits more varied adaptations than in the 
performance on wind instruments. 

The Masseter and Temporal give motion to the lower 
jaw. 

The Sterno-Cleido-Mastoid, when both sides contract, 
draws the head forward or elevates the sternum. 

' MUSCLES OF THE ANTERIOR PART OF THE TRUNK. 

169. The Pectoralis Major draws the arm by the side, 
and across the chest, and also draws the scapula forward. 

The Serratus Magnus elevates the ribs in inspiration. 

The Obliquus Externus and Eectus Abdominalis 
exert an equable pressure upon the organs contained in the 
abdominal cavity ; when acting together they bend the body 
forward or elevate the hips ; they also depress the ribs in 
respiration. When the muscles of but one side act, the body 
is twisted to that side. 

MUSCLES OF THE POSTERIOR PART OF THE TRUNK. 

170. The Trapezius, Khomboideus Major and Minor 
draw the scapula back toward the spine: the two latter 
draw the scapula upward toward the head, and slightly 
backward : the former draws the head back and elevates 
the chin. 

The Latissimus Dorsi draws the arm by the side and 
backward. 

The Serratus Posticus Inferior depresses the ribs in 
expiration. 

MUSCLES OF THE UPPER EXTREMITIES. 

171. The Deltoid raises the arm from the side of the 
body to a horizontal position. 

The Biceps flexes the fore-arm on the arm, as in preparing 
for striking a blow. 

The Triceps extends the fore-arm on the arm ; it lies on 
the back of the humerus and is used in striking a blow. 



78 ANATOMY, PHYSIOLOGY AND HYGIENE. 

Fig. 62. 




Fig. 62. The Dorsal Muscles. — The first, second, and part of the third layer of muscles 
of the back. The first layer is shown on the right, and the second on the left side. 
1, The trapezius muscle. 4, The latissimus dorsi muscle. 5, The deltoid muscle. 7, 8, The 
gluteus medius muscle. 9, The gluteus maximus muscle. 11, 12, The rhomboideus 
major and minor muscles. 16, The serratus posticus inferior muscle. 22, The serratus 
magnus muscle. 

The Flexor Carpi Eadialis passes under the annular 
ligament and bends the hand on the wrist. 

The Flexor Carpi Ulnaris bends the hand in the 
direction of the ulna. 

The Flexor Digitorum bends the fingers. 

The Extensor Digitorum extends the fingers. 

The Extensor Carpi Eadialis extends the wrist on the 
fore-arm. 



THE MUSCLES. 79 

MUSCLES OF THE LOWER EXTREMITIES. 

172. The Glutei give power of retaining the erect posi- 
tion. 

The Sartorius bends the lower extremities into the posi- 
tion assumed by the tailor at his work. 

The Rectus Femoris, Vastus Externus, and Vastus 
Internus extend the leg on the thigh. 

The Triceps Abductor Femoris bends the thigh on the 
pelvis, rotates it outwardly and acts powerfully in bending 
the limbs inward. 

The Biceps Femoris forms the outer hamstring, assists in 
turning the leg outward, and also flexes it upon the thigh. 

The Extensor Digitorium splits into four tendons which 
pass under the annular ligament, and extend the four lesser 
toes and flex the foot. 

The Peroneus Longus extends the foot and inclines the 
sole obliquely outward. 

The Gastrocnemius Externus raises the body in 
walking, and extends the foot on the leg. 

The Tendo- Achilles (heel-cord) is formed by the con- 
joined tendons of the gastrocnemius externus and internus 
(and plantaris). It lies directly beneath the fascia and in- 
teguments. 

\ 14. Histology of the Muscles. — Analysis of a Muscle. Sheaths 
of Muscles. — Voluntary or Striated, and Involuntary or Non-Striated 
Muscle. Exciting Agents of Muscular Contractility. Tendons, Blood- 
Vessels and Nerves. 

173. A Muscle is separable into bundles of fibres called 
Fasciculi; each bundle or fasciculus, into smaller fibres 
(smaller fasciculi) ; each of the smaller fibres, into a multi- 
tude of filaments, or fibrillar (fibrils) ; and each filament, or 
fibrilla, into cells arranged in a linear series. Hence, a single 
muscle is composed of some millions of these fibrillar com- 
bined together, having the same point of attachment or 
origin, and concentrating in a tendon which is fixed to a 
movable part, or the point of insertion. 



80 ANATOMY, PHYSIOLOGY AND HYGIENE. 

174. Each muscle is invested by a membranous covering 
of areolar tissue, named the Perimysium; from this, thin par- 
titions pass inward between the large and small fasciculi, so 
that, were it possible to remove the muscular substance, there 
would remain a delicate areolar network of the exact shape 
of the muscle and its parts. Each elementary fibre or fascic- 
ulus is enclosed in a very thin, transparent, structureless 
sheath, called Myolem'ma; this sheath is entirely distinct from 
that of the areolar tissue ; it isolates each ultimate fasciculus 
and probably gives off a sheath to each fibril. 




Fig. 63 (Lridy). Development of Striated Muscular Fibre, from Cells. — a, Simple 
cell, 6, A pair of cells fused together, c, Three cells fused, and their contents as- 
suming the striated character, d, A muscular fibre, exhibiting its original composi- 
tion of cells. 



175. Muscles are of two classes — Striated and Non-Striated; 
the former are also called Voluntary, being, in their normal 
action, under the control of the will ; the latter, Involuntary, 
acting independently of the will, as the heart, the stomach 
and the intestines. The Myolemma, or sheath, so distinct in 
the striated or voluntary muscle, cannot be shown to exist in 
the involuntary or non-striated muscle. The heart seems to 
be a connecting link between the two classes, as it is involun- 
tary in action, yet composed of striated muscle ; the sheath, 
however, is wanting. 

176. The " Vis Musculosa," or contractility of the muscle, 
is excited on the application of certain stimuli ; these may 
be Mechanical, as the touch of a sharp instrument ; Chemical, 
as acids and alkalies ; Electrical, as in shocks ; and Vital, 
originating in, or acting through, the nervous system : it is 
by means of the latter that muscular fibre is most frequently 
called into action. 



THE MUSCLES. 81 

177. Tendons are composed of the inelastic, white-fibrous 
tissue, and possess great strength. The muscular fibres do 
not cease immediately, but intertwine with those of the ten- 
dons, and these with those of the bone. The tendinous and 
muscular fibres are generally parallel ; thus being straight 
in the sartorius, and oblique in the penniform muscles. In 
passing over bones or other hard parts, they are protected by 
synovial bursse. In common with the muscle to which it be- 
longs, each tendon has an envelope of very condensed areolar 
tissue continuous with that of the muscle : this sheath gene- 
rally forms a semi-cylindrical canal, completed on the oppo- 
site side by the bone, so that the tendon itself slides into a 
canal partly bony and partly fibrous. This canal is lined 
with the synovial membrane. 

178. The Blood- Vessels do not enter the proper mus- 
cular substance, but everywhere abound in the areolar tissue 
by which the fibres are enveloped ; hence the nutriment 
necessary for the growth and repair of muscular tissue must 
be absorbed through the Myolemma. 

179. The Nerves seem to occupy the same position as the 
blood-vessels, in relation to the primitive fibres, and therefore 
must also exert their influence through the Myolemma. The 
nerves of the voluntary muscles are abundant, and chiefly of 
the motor class, or those which preside over motion, having 
nothing to do with sensation, and hence acting from the 
brain and spinal cord to the muscles ; while the nerves of 
the involuntary muscles are few, and of the sensory class, 
or those which preside over sensation, having nothing to do 
with motion, hence conveying impressions to the brain and 
spinal cord. 

\ 15. The Chemistry of the Muscles. — Chemical Composition of 
Muscle. Chemical Changes attending Muscular Action, The Mus- 
cular Current. 

180. The chemical composition of muscular tissue cannot 
be precisely known, because of the difficulty of isolating the 
fibres from the areolar tissue, blood-vessels and nerves blended 

D* 



82 ANATOMY, PHYSIOLOGY AND HYGIENE. 

with them. We give the analysis of Berzelius, by which it 
appears that less than twenty-three per cent, of ordinary 
meat is solid matter : 

Proper muscular substance 15.80 

Gelatin (firm areolar tissue) 1.90 

Albumen and haernatin 2.20 

Phosphate of lime with albumen 08 

Alcoholic extracts with salts (lactates) 1.80 

Watery extracts with salts 1.05 

Water and loss 77.17 

100.00 
Inosit, or Muscle Sugar, exists in the juice of flesh. 

181. The proper muscular substance differs from simple 
fibrous tissue in not being resolved into gelatin by boiling. 
It contains a peculiar principle called os'mazome; this is 
colored, soluble in alcohol, and gives to broth its charac- 
teristic taste and smell. 

182. Muscular action is accompanied by chemical changes 
due to the oxidation of muscular tissue. Quiescent muscle is 
neutral (neither acid nor alkaline) in chemical character ; but 
muscle after repeated contractions is acid. Heat is evolved, 
both by chemical action and increased capillary activity, in 
proportion to the amount of exercise performed. The elec- 
trical current known as the " muscular current" is probably 
a result of chemical action. In the entire muscle, its path 
lies along the outside toward the tendons. The direction of 
the total current of the body is from the head downward. 

Observation. — In friction, or rubbing the body with the 
hand, the direction of the current should be followed, other- 
wise irritation is produced rather than the soothing influence 
desired. This direction is of special importance to nurses 
and watchers in caring for the sick, particularly nervous 
patients; the effect of friction is sometimes improved by 
moistening the inside of the hand. 



THE MUSCLES. 83 

§ 10. Physiology of the Muscles. — Relative Uses of the Bones and 
Muscles. Important Functions of the Muscles. Relation of the Will 
and the Muscular Sense to Muscular Action. The Muscular Sense as 
a Source of Enjoyment. Importance of Involuntary Movements. — Of 
such Movements being sometimes Voluntary. Uses of Tendons. The 
Mechanical Powers as exhibited in Muscular Action. — Levers. — 
Pulley. Oblique Action of the Muscles. Deep-Seated Muscles. 
Minute Muscles. 

183. To give a clear idea of the relative uses of the 
Muscles and Bones, we quote the comparison of another: 
" The Bones are to the body, what the masts and spars are 
to the ship ; they give support and the power of resistance : 
the Muscles are to the bones, what ropes are to the masts 
and spars." 

184. The Uses of the Muscles are manifold — they give 
the beautiful form and symmetry of the exterior of the body ; 
enclose the cavities, and form a firm, defensive, but yielding 
wall in the trunk ; invest and move the bones of the limbs ; 
and give to some of the joints their principal protection. By 
means of the contractile property, and various mechanical 
contrivances of muscular fibres, the heart pulsates; the blood 
circulates ; respiration is carried on ; the conduits of the 
glands urge on their fluids ; and mechanical aid is afforded 
in the various processes of preparing nutriment for the sys- 
tem. We are indebted to the same for our power of locomo- 
tion ; for our ability to engage in the manifold employments 
of life ; to enjoy its pastimes ; and to hold communication 
with our fellow-men by speech, gesture, and the varied ex- 
pressions of the human countenance. 

185. The Voluntary Muscles in their normal condition, 
both in their contraction and relaxation, are subject to the 
control of the Will and the guidance of the Muscular Sense; 
the will determines an act, and the muscular sense enables us 
to judge of the effort necessary to its performance. And here 
we would notice that the motion of a limb implies an active 
state, or a change in both classes of muscles (flexors and ex- 
tensors), the one to contract, the other to relax ; and the will 



84 ANATOMY, PHYSIOLOGY AND HYGIENE. 

influences both classes : the relaxing muscle does not give up 
all effort, but is subject to as fine a sense of adjustment in its 
yielding as in its contraction. 

186. By the aid of the Muscular Sense, sometimes with 
conscious volition, and sometimes without it, we regulate the 
force employed in all the movements of the body, as lifting 
weights ; balancing the body in standing or locomotion ; 
moving the arms in prehensile or manipulating acts ; and 
exercising the vocal organs. The feats of the rope-dancer 
and trained gymnast are largely due to the cultivation of this 
sense. The exercise of the muscular sense is a source of posi- 
tive enjoyment. The person who walks with an elastic step, 
holding the body easily in equilibrium, experiences a sensible 
pleasure unknown to him who moves with shuffling gait and 
apparent distrust of the integrity of his muscles : so in 
dancing, gymnastic and skating exercises, if attention is 
given to elegance of attitude and harmony of motion, there is 
experienced a pleasure quite distinct from that gained by 
the quickened activities, and which is attributable to the 
muscular sense. 

187. The Involuntary Muscles perform their func- 
tions wholly independent of the will, and are essential to 
the action of the heart, the digestive organs, the respira- 
tory apparatus, and various ducts, blood-vessels and lymph- 
atics. The Divine Builder has wisely ordered that these 
vital operations should not be subject to the control of the 
individual. 

188. Again, there are certain operations generally entrusted 
to the involuntary muscles that may be temporarily controlled 
when occasion requires, as in respiration : were these move- 
ments never under the control of the will, we should be un- 
able to use to any advantage the vocal apparatus, either in 
speech or singing, and were we compelled to breathe at per- 
fectly regular intervals, it would be exceedingly difficult to 
attend to the daily duties of life. 

Observation. — In rare instances the action of the heart may 
be suspended for a short time at will. The possibility of such 



THE MUSCLES. 85 

control would be fairly inferred from the presence of striated 
muscular fibre, as before described. 

189. Tendons serve to convey the contractile power of 
muscles to the bones ; they are, in themselves, passive organs 
possessing no contractility. In them the evidence of care 
and skillful arrangement is beautifully exhibited. Wherever 
muscular action is wanted, and the presence of muscle would 
be Jnconvenient or mar the harmony of proportion, or where 
great strength is needed, there we find the small, dense, con- 
ducting tendons : An example is seen in the human hand ; 
Suppose the large muscles of the fore-arm to extend to the 
hand, it would not only be destitute of beauty, but unfitted 
for many of the purposes of life. But the gradual blending 
toward the wrist of the muscles with the tendons ; the band 
clasping them firmly at the wrist; the slits in the short ten- 
dons of the second joint to allow the long tendons to pass 
through to the bones of the fingers, afford the best conceivable 
arrangement for compactness, delicacy, beauty and utility. 



Fig. 6 4. 




2 

Fig. 64 {Leidy). Metacarpal and Phalangeal Bones of the Fingers, with their 
Tendons and Ligaments. — 1, Metacarpal bone. 2, Tendon of the superficial flexor. 
3, Tendon of the deep flexor, passing through a perforation (*) of the superficial flexor. 

190. In the action of the muscles upon the bones, we have 
examples of the three kinds of Levers treated of in mechanics. 
A lever is a rod of wood, metal, or other substance, movable 
in one plane about a supported point in the rod, called a 
fulcrum. The resistance to be overcome, is called the weight ; 
and the force used in overcoming the resistance, is called the 
power. The three kinds of lever are distinguished from each 
other, by the relative position of the power, weight and 
fulcrum. 

191. In the first kind, the fulcrum is between the power 



86 ANATOMY, PHYSIOLOGY AND HYGIENE. 

and the weight ; as in scales, scissors, etc. ; in the second, the 
weight is between the power and the fulcrum ; as is seen in 
moving the common wheelbarrow, or a door; in the third, 
the power is between the weight and the fulcrum ; as in using 
the fire-tongs. In the body, the bones are the levers ; the 
parts attached, the weights ; and the muscles, the powers. 
The fulcra are the joints, or extremity of the limbs in contact 
with the ground, or other resisting substance. 

192. The first kind of lever is illustrated in the adjustment 
and movement of the skull upon the first vertebra (91) ; the 
hinge-joint is the fulcrum ; the excess in gravity of the parts 
of the head in front of the joint over the parts behind it, is 
the weight ; and the muscles extending from the spine to the 
cranium are the power. Of the same kind of leverage, are 
the movements of the vertebrae on each other from above 
downward ; of the lowest lumbar vertebra on the sacrum ; of 
the pelvis on the thigh-bone; of the thigh on the leg; of 
the leg on the ankle ; and also the extension of most of the 
joints of the upper extremities — as the elbow and the joints 
of the fingers. 

193. The second kind of lever is illustrated in the foot. 
When resting on the ground, with the heel raised, the ful- 
crum is at the ball of the great toe ; the weight is the body 
transmitted through the large bone of the leg ; and the power 
is in the muscles of the calf of the leg (Gastrocnemii) acting 
through the tendon of Achilles (Fig. 61). The depression 
of the lower jaw, when the mouth is opened very wide, is 
also an example of the second class. Where great weight is 
to be raised slowly through a short space, we find the second 
class of levers. 

194. The third kind of lever is most used in animal me- 
chanics ; as in raising the lower jaw ; in raising the shoulder 
and collar-bone, and in the flexion of all the joints of the 
limbs. A familiar example is the elbow. The fulcrum is 
at the joint ; the weight is the fore-arm and hand ; and the 
power is in the biceps and brachial muscles. This kind of 
lever works at what is called a mechanical disadvantage, as 



THE MUSCLES. 



87 



the distance of the power from the fulcrum is always less 
than that of the weight; and the shorter the power-arm 
(or distance of the power from the fulcrum) in proportion 
to the weight-arm (or distance of the weight from the ful- 
crum), the greater must the power be to overcome a given 
resistance ; but what is lost in power, is gained in velocity. 
In mechanics, one of two things is aimed at — either to raise 
a great weight slowly and through a short space, or to move 
a light weight quickly through a long space ; the latter is 
most frequently needed for the purposes of life, hence, w T e 
find it accomplished by the use of levers of the third class. 

Fig. 65. 




Fig. 65. Diagram of the Third Kind of Lever. — 1, The bone of the arm above the 
elbow. 2, One of the bones below the elbow. 3, The muscle that bends the elbow. 
This muscle is united, by a tendon, to the bone below the elbow (4) ; at the other ex- 
tremity, to the bone above the elbow (5). 6, The muscle that extends the elbow. 7, Its 
attachment to the point of the elbow. 8, A weight in the hand to be raised. The 
central part of the muscle 3 contracts, and its two ends are brought nearer together. 
The bones below the elbow are brought to the lines shown by 9, 10, 11. The weight is 
raised in the direction of the curved line. When the muscle 6 contracts, the muscle 3 
relaxes and the fore-arm is extended. 



195. There is a loss of power, and hence mechanical dis- 
advantage, in the oblique action of the muscles, since a force 
acting perpendicularly on the arm of a lever, operates most 
advantageously. It is important to notice, however, that the 
tendons of insertion, and sometimes also those of origin, are 
attached to the special eminences of bones called processes, 



88 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



in which case the muscles gain an advantage, for their force 
ultimately operates in a line more or less perpendicular to 
the osseous surface, instead of in a line nearly parallel with 
it, as would happen if there were no elevations. The ex- 
tensors act more obliquely than the flexors, and therefore 
require an additional amount of fibres, hence, they are larger 
than the flexors, in the ratio of eleven to five. 

196. The principle of the pulley is also used in the arrange- 
ment of the muscles, though less frequently than the lever. 
The annular ligaments, which confine the tendons at the 
wrist, and at the ankle (61), act as pulleys. A marked 
example is seen in one of the muscles that pull down the 
lower jaw, called the digastric muscle; this has one extremity 
attached to the inside of the lower part of the chin-bone, and 
the other to the back of the ear ; it is tendinous in its middle 
portion, which passes through an opening in a short muscle 
connecting the hyoid bone, just above the larynx, to a small 
process under the ear ; hence, when the digastric muscle con- 
tracts, the jaw is depressed. Another beautiful example is 
furnished by the trochlear muscle of the eye (Fig. 181). 



Fig. 66. 




Fig. 66. Pulley Arrangement of a 
Muscle. — 1, Digastric muscle attached 
to the mastoid process of the temporal 
bone behind the ear. 2, Its attach- 
ment to the lower jaw. 3, Hyoid bone. 
4, The pulley arrangement of the di- 
gastric and stylo-hyoid muscles. 



197. We have noticed only the larger of the exterior layer 
of muscles. The limits of this work will not allow a full view 
of the exquisite beauty beneath ; the layers are of various 
sizes and forms, and crossing each other in every direction, 
yet the millions of fibres and multiplied millions of cells per- 



THE MUSCLES. 89 

form their assigned work in perfect harmony, not one inter- 
fering with the action of another. In the abdominal muscles, 
one layer of muscles is oblique from left to right toward the 
median line; another crosses this diagonally from right to 
left ; another crosses these transversely ; and still another 
perpendicular layer overlies all the others. 

19S. Infinite mechanical skill is still more wonderfully 
shown in the nice adjustment and accurate movements of the 
minute muscles, as those of the tongue, and the yet finer 
muscles of the eye and the drum of the ear, too small to be 
seen by the naked eye. 

199. Everywhere the muscular force is one and the same, 
but its applications are innumerable; the instruments are 
constructed upon the same plan, but infinitely varied in form, 
size and arrangement, yet made with the greatest simplicity 
for effecting each its particular purpose. 

"In human works, though labored on with pain, 
A thousand movements scarce one purpose gain; 
In God's, one single can its ends produce, 
Yet serves to second, too, some other use J 1 



§ 17. Hygiene of the Muscl.es. — Requirements necessary to main- 
tain a Healthy Condition of Muscle. Importance of Freedom from Com- 
pression. — Of Exercise. Conditions to be observed in Muscular Exercise. 
Exercise sometimes Injurious. Effect of Mental Stimulus. Regard 
necessary to the Age and Health. — Position of the Body. — Proper Mus- 
cular Tension. Education of the Muscles. 

200. Since so much of our happiness and usefulness in life 
depends upon healthy muscle, it is of great importance that 
we seek to understand the laws upon which their normal 
action depends. The first and great essential is, that the 
muscles should be abundantly supplied with pure blood. A pure 
state of the blood requires that the digestive apparatus should 
be in a healthy condition ; that the vital organs should have 
ample volume ; that the lungs should be plentifully supplied 
with pure air ; that the skin should be kept warm by proper 

8* 



90 ANATOMY, PHYSIOLOGY AND HYGIENE. 

clothing, and clean by bathing, and that it should be acted 
upon by air and sunlight It is also of primary importance 
that there be free circulation of the blood, which may be 
secured by freedom from compression, and by regular and 
judicious exercise, 

201. Freedom from compression is requisite to free circula- 
tion, for, even a slight pressure upon the delicate, yielding 
blood-vessels checks the flow, thus preventing the necessary 
deposit of materials required by the waste of the system, and 
also the removal of the injurious products of the decomposing 
tissues. Again, pressure stimulates the lymphatics to undue 
action, thus attenuating the muscles. 

A fractured limb is enfeebled, not only by inaction, but by 
the necessary pressure of the dressing ; it recovers its size, tone 
and strength only by judicious and persistent exercise after 
the bandages are removed. 

The pressure of tight dresses, under the name of a " neat 
fit," not only produces deformity in the general figure, but 
prevents the expansion of the lungs, and stagnates the blood, 
thus poisoning the whole system. 

The young lady who is " horrified" at the act which takes 
life in a moment, adopts a plan no less suicidal. She is 
equally certain to take away her God-given life. And if the 
guilt of self-murder admits of degrees, shall he who applies 
the knife to his throat, or the rope to his neck, be guilty of a 
greater condemnation, than she who extends the act through 
months, or, if nature endures, through years, meanwhile 
poisoning the soul as well as the body ? 

202. Free circulation, and, consequently, muscular power, is 
increased by proper exercise, and decreased by inactivity. It is 
a general law of the system, that the action and power of an 
organ are, within a certain limit, commensurate with the de- 
mand made upon them — a law which holds good in the mus- 
cular apparatus. When the muscles are exercised, the flow 
of blood in the arteries and veins is increased, hence, the 
muscular fibre increases in size, and acts with greater force ; 
while, on the contrary, the muscle that is little used receives 



THE MUSCLES. 91 

little nutriment from the sluggish blood, and decreases in size 
and power. 

Illustration. — The muscles of the blacksmith increase in 
size and become firm and hard ; those of the student, if not 
used in gymnastics or otherwise, decrease in size and become 
soft and les3 firm. 

203. Relaxation must follow contraction, or rest must follow 
exercise. Exercise too long continued produces exhaustion, 
and' in the exercise of exhausted muscle, the loss of material 
exceeds the deposit.; also long-continued tension enfeebles, 
and at length destroys the contractile property. 

Illustration. — The effect of over-work may be seen in the 
attenuated frames of over-tasked domestic animals, as the 
horse, or in the diminished weight of the farmer after the 
hurry of harvest-time. The effect of continued tension is 
seen in the restlessness of children at school, after sitting for 
a time in one position. The necessity of frequent recesses is 
founded upon the organic law, that relaxation of muscle 
must follow contraction. The younger and feebler the pupils, 
the greater is this necessity. 

204. Change of employment often affords the required rest, 
as it brings into action a new set of muscles ; hence, the per- 
son of sedentary occupation is rested by general muscular 
exercise, while the person of active occupation is rested by 
that of a sedentary character. 

Illustration. — The needlewoman exhausts the muscles of 
the back and arm ; a brisk walk or some active household 
employment affords rest. 

205. The muscles should be gradually called into action; for 
while in action, they require more blood and nervous fluid 
than when at rest, and these fluids are gradually increased. 
In an alarm of fire, never start " on the run," but " make 
haste slowly" in the first instance, and then gradually in- 
crease your speed. 

Observation. — If a man has a certain amount of work to 
perform in nine hours, his muscles having been in a state of 
rest, he will do it with less fatigue by performing half the 



92 ANATOMY, PHYSIOLOGY AND HYGIENE. 

work in the first five hours, and the remainder in four hours. 
The same principle applies in the use of beasts of burden, or 
in driving the carriage-horse. 

206. The muscles should be rested gradually after vigorous 
exercise. If a person has made great muscular exertion, in- 
stead of sitting down immediately to rest, he should continue 
to exercise moderately for a short time, and avoid sudden 
cooling in a current of air; additional clothing is often 
needed. The soreness of muscles which have been severely 
exercised, is often prevented by bathing and thorough rub- 
bing, followed by moderate exercise. 

207. Exercise should be regular and frequent. The system 
needs this means of invigoration as regularly as it needs new 
supplies of food. To devote a few days to the proper action 
of the muscles, and then spend a day inactively, is as incor- 
rect as to take a proper amount of food for a time, and then 
to withdraw the supply for a season. The industrious artisan 
and the studious minister suffer as surely from undue physical 
inactivity, as the indolent man. The evil consequences of 
neglect of regular exercise steal slowly but surely upon an 
individual ; sooner or later they are manifested in muscular 
weakness, dyspepsia and nervous irritability. 

208. Every part of the muscular system should have its ap- 
propriate share of exercise. Farming and domestic employ- 
ments are superior as vocations, in respect to giving all the 
muscles their due proportion of action. Where the daily 
occupation exercises but a part of the muscles, it should be 
followed by some employment or recreation which will bring 
the others into use. Among the healthful pastimes, are those 
of quoits and ball-playing. Students, both boys and girls, 
often become chronic invalids from the want of this general 
exercise. Every institution, having no arrangement for sys- 
tematic physical exercise, should be considered as wanting 
in one great means not only of physical, but of intellectual 
and moral development. If possible, there should be a gym- 
nasium with its varied appurtenances ; if not, there should, 
at least, be a room where light gymnastics may be practiced 



THE MUSCLES. 93 

daily, and this should not prevent further exercise in the 
open air. Experience has proved that far more intellectual 
vigor is gained when this practice is observed. 

209. The amount of exercise should be adapted to the age 
and strength of the individual. In youth, a portion of the 
vital, or nervous energy of the system, is expended upon the 
growth of the organs of the body, consequently, severe labor 
or exercise is injurious. 

Observation. — In the campaigns of Napoleon Bonaparte, 
his army was frequently recruited by mere boys. He com- 
plained to the French government, because he was not sup- 
plied with mature men, as the youths could not endure the 
exertions of forced marches. 

210. The proper time for exercise should be observed. As a 
general rule, the morning is a better time for exercise than 
the evening ; the powers of the system are greatest at that 
time. Severe exercise should be avoided immediately before 
or after a meal ; the vigor of the system is then required for 
the digestive functions. The same rule should be observed 
regarding mental toil, as the powers of the system are then 
concentrated upon the brain. 

Observation. — When an organ is in functional action, it 
attracts fluids (sanguineous and nervous) from other organs 
of the system. The vital energies are sufficient for this one 
work ; but if two important organs are called into intense 
activity, injury arises to both and also to the general system. 
Nature can sustain in vigorous activity but one function 
at a time. 

211. The mind exerts a great influence upon the tone and 
contractile energy of the muscles. Muscular exercise will be 
attended with much less fatigue, when the muscles act under a 
healthy mental stimulus. This we see illustrated in the ordi- 
nary vocations of life ; if the mind has some incentive, the 
tiresomeness of labor or exercise is greatly diminished : 

"He chooses best whose labor entertains 
His vacant fancy most ; the toil you hate 
Fatigues you soon, and scarce improves your limbs." 



94 ANATOMY, PHYSIOLOGY AND HYGIENE. 

The effect of the mind upon the muscles is seen in the spirit- 
less aspect of many of our boarding-school processions, when 
a walk is taken merely for exercise, with no other object in 
view. But, present to the mind a botanical or geological ex- 
cursion, and the saunter will be exchanged for the elastic 
step, the inanimate appearance for the bright eye and glow- 
ing cheek. The difference is, simply, that in the former case, 
the muscles are compelled to work without the nervous im- 
pulse, which, in the latter case, is in full and harmonious 
operation. It must not be supposed that a walk simply for 
exercise is not beneficial ; if possible it should be taken in 
combination with harmonious mental exhilaration ; if not, 
let the position be erect and the^pace so brisk, as to produce 
rapid respiration and circulation of the blood, and in a dress 
that shall not interfere with free motions of the arms and 
free expansion of the chest. 

212. The amount of exercise should be adapted to the health 
of the individual. This direction is of essential importance, 
for what gives vigor to one, may bring weakness to another. 
A walk which would invigorate one in health, will quite ex- 
haust a feebler person ; hence, the measure of strength must 
be the measure of exercise; but a careful distinction should 
be made between simply healthful fatigue, s^on removed by 
subsequent rest, and the positive exhaustion which really en- 
feebles. 

213. In diseases producing great muscular exhaustion, par- 
ticular care and discretion are necessary regarding exercise. In 
scarlet fever, typhoid diseases, etc., the muscular debility is 
very great ; and any muscular exertion that exhausts, such 
as moving the patient home when he has sickened abroad, 
or undue exercise during convalescence, is almost sure to re- 
sult injuriously, if not fatally. Exercise should be moderate, 
made pleasant, and followed with proper intervals of rest, 
and never at the discretion of one who is ignorant of the pecu- 
liar state of the system. 

214. In chronic diseases of the digestive organs, lungs and 
nervous system, well-directed and persistent exercise of the muscles 



THE MUSCLES. 95 

is essential to recovery. In these ailments, the exertion of all 
the muscles repeated frequently, is attended with the most 
compensatory results. Moderation is necessary at first, but 
the exercise should be increased in intensity and duration. 
The aversion of the patient to exercise is often very great ; 
but it should, nevertheless, be persistently taken in the same 
spirit in which he would perform any other part of the life- 
work entrusted to him. Making it a business to perform the 
labor necessary to recovery, and entering into it with the 
heart and the will, gives the healthy tone and stimulus so im- 
portant in securing the most beneficial results. 

Observation. — A patient who had suffered long from a 
combination of chronic ills which baffled the skill of several 
physicians, in extreme weakness, adopted a systematic plan 
of exercise, commencing with but two or three steps at a 
time, and adding a step or two each day, till in six months' 
time she walked regularly three miles a day. 

215. The muscles require an erect position of the body both 
in standing and in sitting. A person can stand longer, 
walk farther, and perform more labor in an erect position 
than when stooping, since fewer muscles are then in a state 
of tension, and, consequently, less draught is made on the 
nervous system. While stooping, the muscles of the posterior 
part of the spinal column are kept in a state of tension, to 
prevent the body from falling forward ; while in the erect 
position, the body and head are balanced upon the bones and 
cartilages of the spinal column. In stooping, the lower limbs 
are also curved at the knee, causing a constant tension of 
their muscles ; again, the slight oscillation is wanting, which 
in the erect position gives alternate contraction and relaxa- 
tion of the muscles of the back. 

216. It is important that the muscles of the child should 
receive due attention, that the shoulders may be thrown 
back, and the chest become broad and full. Even when an 
adult has contracted the habit of stooping, and has become 
round-shouldered, it can be measurably, and generally wholly 
corrected, by moderate and repeated efforts to bring the shoul- 



96 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



ders into proper position. This deformity should receive 
attention in our schools. It may be remedied as well by 
persistent effort on the part of a kind instructor, as u»der 
the stern military drill-sergeant, who never fails to secure 
the erect attitude in his raw recruits. In furnishing school- 
rooms with desks, care should be taken that they be of suffi- 
cient height to allow the proper attitude when pupils are 
using their books or the pen. This is not only essential to 
health, but to beauty and symmetry of form. 



Fig. 67. 



Fig. 68. 




Fig. 67 represents the Erect Position of the Body. 1, A perpendicular line from 
the centre of the feet to the upper point of the spinal column, where the head rests. 
2, 2, 2, Spinal column with its three natural curves. The head and body are so balanced 
that the muscles are not kept in a state of tension. 

Fig. 68 represents the Stooping Position of the Body. 1, A perpendicular line. 
2, Unnatural curved spinal column, and its relative position to the perpendicular line (1). 
The curved position of the body and lower limbs keeps the muscles in tension, which 
exhausts their contractile energy. 



THE MUSCLES. 



97 



Observation. — A simple test of the erect position is to stand 
with the back against the wall of a room, with the heels, 
elbows and back of the head touching the wall. The effort 
required to do this will show the amount of the departure 
from the true attitude. 



Fig. 69. 



Fig. 70. 




Fig. 69 represents an Improper, but not an unusual, position when writing. 
Fig. 70 represents a Proper position when writing. 



217. J. slight relaxation of the muscles tends to prevent their 
exhaustion. In walking, dancing, and most of the mechanical 
employments, the fatigue will be less, and the movements 
more graceful, if the muscles are slightly relaxed ; the same 
condition diminishes the jar of cars or coaches. In jumping 
or falling from a carriage or any height, the shock will be in 
a measure obviated if the presence of mind is sufficient to 
relax the muscles, bend the limbs at the ankle, knee and 
hips; throw the head and body slightly forward, and fall 
upon the toes, instead of the heel. 

Observation. — With the lower limbs firm and the muscles 
9 E 



98 ANATOMY, PHYSIOLOGY AND HYGIENE. 

rigid, jump a few inches perpendicularly to the floor, and 
fall upon the heels ; again, slightly bend the limbs, jump a 
few inches and fall upon the toes, and the difference in the 
force of the shock ^ ill be readily noticed. 

218. The muscles require to be educated or trained. Fre- 
quent and systematic use of the muscles at proper intervals 
is necessary to effective action. This education must be con- 
tinued till not only each muscle, but every fibre of the muscle, 
is fully under the control of the will. In this way, persons 
become skillful in every employment. The power of giving 
different intonations in reading, speaking, and singing; the 
rapid movements in penmanship, and in mechanical and 
agricultural employments, depend, in a great measure, upon 
the education of the muscles. An individual with trained 
muscles will perform a given amount of labor with less 
fatigue and waste to the system than one whose muscles are 
untrained. 

Observation, — It is exceedingly important that correct 
movements be insisted upon at the commencement of any 
muscular training, as it is very difficult to change a move- 
ment which has been long practiced. If a child holds his 
pen improperly during his early lessons, he will probably 
never become an easy and elegant writer. 



\ 18. Comparative Myology. — Compare Muscles of other Mammals 
with those of Man. Muscles of Birds — Of Rept lies — Of Fishes. 

219. The muscles of all Mammals in their general plan, 
resemble those of Man ; the modifications in number, form, 
position and relative size, being only such as adapt them to 
the habits and necessities of the particular species. The 
color of the muscle is deepest in the Carnivora (flesh-eaters), 
and palest in the Rodentia (gnawers). 

220. The muscular system of Birds is remarkable for the 
distinctness and density of their fasciculi, for the deep-red 
color of those employed in vigorous action, and their marked 
separation from the tendons, which are of a pearly-white 



THE MUSCLES. 



99 



color and have a peculiar tendency to ossification. This high 
development results from the rapid circulation of warm, 
rich, highly oxygenated blood through the extent of the 
respiratory system. The energy of the muscular contraction 
in this class is in the ratio of the activity of the vital func- 
tions. As in Mammalia, so in birds, the muscles are varied 
to meet the habits, wants and condition of the several species 

and orders. 

Fig. 71. 




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is s 3 

? • s 

'2 « 'to 

J 72 .2 
II;--? 

° - s 



I ft a 

C co c« 

£ .§ §J 

6 S -g 

."£ 53 e3 

■s >3 

O ^ S 



>» 



o P* 



D 06 " 

O * ^ 

5 v » 

tf o £ 






221. The muscles of the air-breathing Reptiles are always 
pale in color, and the fibres are tenacious of their contractility; 



100 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



the energy of their contraction in some instances and on 
some occasions is great, but it cannot be continuously exer- 
cised, such power being soon exhausted. The form, size and 
relative number of the muscles are as various as in mammals 
and birds. 

Fig. 12. 



S 3 



K3 



to ? 

o 

el ? 

II 



H 9 1 



^22 
8 d 2. 









o r 

O CO 

cc - 
If 




In reptiles the muscular system of the trunk reaches its 
maximum development in serpents, and its minimum de- 



THE MUSCLES. 



101 



velopment in the tortoise. The mandibular development is 
generally large, while that of the limbs is comparatively small 
or entirely wanting. 

Fig. 73. 




Fig. 73. Muscles of the Tortoise. — 1, Digastricus. 2, 3, Deltoides. 4, Serratus Mag- 
nus. 5, 6, Triceps Brachii. 7, Biceps Brachii. 8, Uluaris Interims. 9, Flexores Digi- 
torum. 10, Sartorius. 11, 12, Gastrocknemius. 13, Triceps Adductor. 

222. In Fishes there is a modification of the active motor 
organs, and a marked deviation from the fundamental ver- 
tebral type. The chief masses of the muscular system are 
disposed on each side of the trunk in a series of vertical 
plates, or flakes, corresponding in number to the vertebrae. 
Each ]ateral flake (myocomma) is attached by its inner bor- 
der to the osseous and fibrous parts of the corresponding seg- 
ment of the skeleton within ; by its outer border, to the skin ; 
and by its fore and hind surfaces, to the septum between it 
9* 



102 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



and the contiguous myocommas, or flakes. The gelatinous 
tissue of these septa is dissolved by boiling, and the muscular 
segments, or plates, are then easily separated, as we find in 
carving fish for the table. Each flake is arranged in a zig- 
zag manner. The muscular tissue of fishes is usually color- 
less, sometimes it is opaline or yellowish, but it is white when 
boiled. 

Fig. 74. 




Fig. 74. Muscles of the Fish.— a, b, c, The zigzag arrangement of the myocomma. 



DIVISION III. 

THE NUTRITIVE APPARATUS. 

223. In the mastication and deglutition of food ; in its 
conversion into fluids ; in its circulation in all parts of the 
system ; in its assimilation into the various tissues and organs 
of the body ; in its dis-assimilation, and in the excretion of 
useless matter ; — in a word, in the building up and repairing 
of the system, from the earliest period of embryo life to the 
last moment of earthly existence, certain organs are used, 
which together may be termed the Nutritive Apparatus : 
including the Digestive, the Absorptive, the Circulatory, the 
Assimilatory and the Respiratory organs. 



CHAPTER VI. 

THE DIGESTIVE ORGANS. 



§ 19. Anatomy of the Digestive Organs. — Anatomy of the Mouth. 
— The Teeth. — The Salivary Glands. — The Pharynx. — The (Esophagus. 
— The Stomach. — The Intestines. — The Liver. — The Pancreas. — The 
Spleen. 

224. The Digestive Organs include the Mouth, Teeth, 
Salivary Glands, Palate, Pharynx, (Esophagus, Stomach, Intes- 
tines, Liver, Pancreas and Spleen. 

225. The Mouth is the space bounded by the lips in front ; 
the soft palate behind, which separates it from the pharynx ; 
the hard palate above, enclosed by the teeth and alveolar 
arch ; and the floor below, upon which rests the tongue (the 
floor being included within the lower teeth and alveolar 
arch). 

103 



104 ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 75. 




THE DIGESTIVE ORGANS. 



105 



226. The Teeth are attached to the upper and the lower 
jaw-bone by means of bony sockets called alve'olar processes. 
The attachment is strengthened by the fibrous, fleshy struc- 
ture of the gums. Each tooth has two parts — the crown and 
the root: the crown is that part which protrudes from the 
jaw T -bone and gum, and is covered by the enamel ; the root, 
or fang, is that part contained in the socket of the jaw ; and 
the slight]y constricted portion clasped by the gums is the 
neck. 

Fig. 76. 




Fig. 76 represents the Adult Teeth. — 1, 2, The cutting teeth (incisors). 3, Eye-tooth 
(cuspid). 4, 5, Small grinders (bi-cuspids). 6, 7, 8, Grinders (molars). 9, 9, Neck of the 
tooth. 

Observation. — These bony processes are absorbed after the 
extraction of a permanent tooth, leaving the jaw-bone covered 
only by the lining membrane of the gum. This gives the 
narrow jaw and retreating lips of old age. A piece of the 
alveolar process sometimes clings to a tooth when extracted^ 
and the dentist has the credit of " breaking the jaw." 

227. The first set of teeth, appearing in infancy, is called 
temporary, or the milk-teeth. They are twenty in number; 
ten in each jaw. Between six and fourteen years of age, they 
are replaced by the second set, called permanent teeth, num- 
bering thirty-two, sixteen in each jaw. 

E* 



106 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



The four front teeth in each jaw are called Incisors (cutting 
teeth). They are convex in front, concave behind, gently- 
rounded at the sides, and have a broad, chisel-shaped body, 
based on a rounded neck, terminating above in a sharp and 
slightly serrated cutting edge. The next tooth on each side, 
the Cuspid (eye-tooth in the upper jaw, and stomach-tooth in 
the lower) is round, strong, with a very long, tapering root, and 
the body terminating in a point having on each side a partial 
serrature : the next two, Bi-cuspids (small grinders) have a 
rounded body terminating on its grinding edge in two points, 
one before, the other behind, with a rough groove between 
them : the next two, Molars (grinders), situated behind all 
the other teeth, have a crown, square or cuboid in form, with 
four points on the triturating surface separated by channeled 
depressions ; the last molar is the dens sapientice, or " wisdom 
tooth/' smaller than its fellows, late in its development, and 
early in its decay. 



Fig. 77. 



Fig. 78. 




Fig. 77. The Mouth and Neck laid Open.— 1, The teeth. 3, 4, Upper and lower jaws. 
5, The tongue. 7, Parotid gland. 8, Sublingual gland. 9, Trachea (wind-pipe). 10, 11, 
(Esophagus (gullet). 12, Spinal column. 13, Spinal cord. 

Fig. 78. A Side View of Face.— 1, 2, Trachea. 3, (Esophagus. 7, Submaxillary. 
8, Parotid gland. 9, Duct from the parotid gland. 4, 4, 4, 5, 6, Muscles. 



The incisors, cuspids and bi-cuspids have each but one 
root; the molars of the upper jaw have three roots; those 
of the lower jaw, two roots. 



THE DIGESTIVE ORGANS. 107 

228. The Salivary Glands consist of three pairs — the 
Parot'id* the Submaxillary and the Sublingual. 

The Parotid Gland, the largest, is situated in front of 
the external ear, and behind the angle of the jaw. A duct 
(Steno's) from this gland opens into the mouth opposite the 
second molar tooth of the upper jaw. The Submaxillary 
Gla^d is situated within the lower jaw, anterior to its angle. 
Its excretory duct (Wharton's) opens into the mouth by the 
side of the frce'num ling'uai (bridle of the tongue). The Sub- 
lingual f Gland is elongated and flattened, and situated 
beneath the mucous membrane of the floor of the mouth, on 
each side of the frsenum linguae, by the side of which are 
seven or eight small ducts opening into the mouth. 

Observation. — The "mumps" is a disease of the parotid 
gland, and the swelling under the tongue, called the "frog," 
a disease of the sublingual gland. 

229. The Pharynx, or throat, is the funnel-like cavity 
about four inches in length, extending from the base of the 
skull to the top of the fifth cervical vertebra, where it be- 
comes continuous with the oesophagus. The pharynx has 
four passages ; one leading upward and forward to the nose ; 
the second, forward to the mouth ; the third, downward to 
the trachea and the lungs ; and the fourth, downward and 
backward to the stomach. 

230. The QEsophagus is a large membranous tube, ex- 
tending from the pharynx to the stomach. It lies behind 
the trachea, the heart and the lungs, and passes through the 
diaphragm. 

231. The Stomach is a somewhat pear-shaped dilatation 
of the alimentary canal. When moderately filled, it mea- 
sures twelve inches in length, by four inches in diameter. It 
has two openings, one connected with the oesophagus, called 
the cardiac orifice ; the other connected with the upper por- 
tion of the small intestine, called the pyloric orifice. 

* Gr., para, near, and ous, ear. 

f Lat., sub, under, and lingua, the tongue. 



108 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



232. The Intestines are divided into the Small and the 
Large intestines. The small intestine is about twenty-five 
feet in length, and divided into three parts — the Duode'num, 
the Jeju'num and the IX cum. 



Fig. 70. 




Fig. 79 (Leidy). The Stomach and Intestines. — 1, Stomach. 2, Duodenum. 3, Small 
intestine. 4, Termination of the ileum. 5, Coecum. 6, Yermi form appendix. 7. Ascend- 
ing colon. 8, Transverse colon. 9, Descending colon. 10, Sigmoid flexure of the colon. 
11, Rectum. 12, Spleen. 

Duodenum signifies twelve, and this part is so called be- 
cause its length is about twelve fingers' breadth, or ten 
inches ; Jejunum signifies fasting, the food passing quickly 
through this portion, leaving it empty ; Ileum, hoisted, is so 
named from its numerous coils or convolutions. 

233. The large intestine, about five feet in length, is also 
divided into three parts — the Coecum, the Colon and the 
JRectum: The Ccecum is so called from its forming a blind 



THE DIGESTIVE ORGANS. 109 

pouch perforated at one end only ; the Colon, because the 
excrements are arrested, for a considerable time, in its folds ; 
and the Kectum, from its straight course. 

Attached to the extremity of the coecum is the appendix 
vermiformis, a, worm-shaped tube, about four inches long, and 
the size of a goose-quill. Its function is unknown. The 
Colon is divided into three parts — the ascending, the trans- 
verse and the descending ; the lower portion of the descending 
coltin makes a double curvature, called the sigmoid flexure. 
The Kectum extends from the sigmoid flexure to the terminus 
of the intestinal canal, a distance of six or eight inches. 

234. The Liver is the largest glandular organ in the body, 
weighing about four pounds. It is situated in the right side 
below the diaphragm. It is convex above and slightly con- 
cave below ; its convex surface being fitted accurately into 
the concavity of the diaphragm, and its concave surface in 
contact with the stomach, duodenum, colon and right kidney. 
The liver is surrounded by a peritoneal covering, which forms 
for it a suspensory, or broad ligament, and two lateral and 
triangular ligaments. It has two principal lobes, the right 
lobe being four or five times larger than the left. On the 
under side of the liver is the gall-bladder, or reservoir for 
the bile, which opens by the common biliary duct into the 
duodenum. 

235. The Pancreas* is a long, flattened organ, weighing 
three or four ounces, about six inches in length, and placed 
transversely across the posterior wall of the abdomen, behind 
the stomach. A duct from this organ opens into the duo- 
denum. 

236. The Spleen (so called because the ancients supposed 
it to be the seat of melancholy) is an oblong, flattened organ 
situated on the left side in contact with the diaphragm, 
stomach and pancreas. It is of a dark-bluish color, has no 
outlet, and its use is not well determined. 

* Gr., 'pan, all, and kreas, flesh. 
10 



110 



\ 20. Histology of the Digestive Organs. —Lining Membrane 
of the Alimentary Canal — Of the Mouth. Histological Composition of 
the Teeth — Of the Tongue — Of the Palates — Pharynx. The Three 
Coats of the (Esophagus, the Stomach and the Intestines — Their Rela- 
tion to each other — Adaptation to their several Offices. 

237. The alimentary canal is lined through its entire 
length by the mucous membrane, which, with its little re- 
cesses forming tubes or sacs called glands, is composed of 
three layers — the epithelium, or surface layer, the basement 
membrane, and the areolar- vascular layer, or corium. The 
epithelium varies in different parts, both in the number of 
layers and in the form of its cells. 

238. The cavity of the Mouth, excepting the teeth, is 
everywhere covered with a highly vascular mucous mem- 
brane, having a squamous epithelium, beneath which are 
concealed conical papillse, excepting upon the gums and 
upper surface of the tongue, where they become conspicuous 
as organs of taste. 

The Tongue is a muscular organ, composed of two sym- 
metrical halves, separated by a median fibrous membrane. 
Its muscles are named extrinsic and intrinsic; the former, 
four in number on each side, pass into the tongue at its base 
and under surface, attaching it to the neighboring parts. 
The intrinsic are named the superior longitudinal, the inferior 
longitudinal, and the transverse; the first extending just be- 
neath the mucous membrane, from the apex, through the 
entire length, to the hyoid bone, having some of its fibres 
oblique, and some branching ; while the inferior longitudinal 
extends from the apex to the base of the tongue. The trans- 
verse muscles which give the principal body to the tongue, 
are connected with the median septum and pass outward, 
intersecting at the margins and base with the other muscles. 
(From this variety of arrangement, the tongue is capable of 
moving in all directions.) 

The Palate, or roof of the mouth, comprises two parts, 
the hard and the soft palate. The Hard palate is deeply 
vaulted and lined with a smooth mucous membrane, except- 



THE DIGESTIVE OKGANS. 



Ill 



ing at the fore part, which is roughened by transverse ridges. 
The Soft palate is composed of a doubling of the mucous 
membrane, enclosing a muscular layer, together with several 
small glands. It projects as a freely movable partition, 
obliquely downward and backward from the hard palate 
between the mouth and posterior nasal orifices. 

239*. The Teeth are appendages developed in the mucous 
membrane of the mouth, and not parts of the skeleton, as is 
sometimes supposed. The tooth consists of a hard portion 
hollowed out and filled with a soft substance, called pulp. 
This pulp is formed of areolar tissue supplied with vessels and 
nerves, which enter the tooth at a minute opening at the point 
of the fang. It is the remains of vascular and nervous papillae 
upon which the tooth was originally formed The hard sub- 
stance is composed of ivory, or dentine, enamel and cement 
The Dentine forming the greater part of the tooth consists 
of microscopic tubes called dental tubuli. These tubuli are 
filled with minute processes of the pulp, affording nutrition 
and perhaps giving sensibility to the dentine. 



Fig. 80. 




Fig. 80 {Leidy). Vertical Section of a Molar Tooth, moderately magnified. 1, 
Enamel, the lines of which indicate the arrangement of. its columns. 2, Dentine, the 
lines indicating the course of its tubules. 3, Thin lamina of the dentine forming the 
wall of the pulp cavity, the dots indicating the orifices of the dental tubuli. 4, 
Cement. 



112 ANATOMY, PHYSIOLOGY AND HYGIEKE. 

The crown of the tooth is covered with Enamel, the hardest 
of all known animal textures, containing more earthy matter 
than the dentine, chiefly phosphate of lime. The enamel is 
composed entirely of hexagonal, prismatic fibres or rods 
arranged closely together upon the dentine. On the crown 
these fibres are vertical ; on the sides, they become first 
oblique, then horizontal. 

The Cement is a thin layer of true bone covering the fang, 
thinnest next to the enamel, and thickest along the grooves 
and near the point. Its outer surface is firmly attached to 
a fibro-vascular and sensitive membrane analogous to the 
periosteum, which seems to fasten the teeth in the socket of 
the jaw, being itself united to the periosteal membrane which 
lines its sockets. 

240. The Pharynx is a musculo-membranous bag, attached 
above to the base of the skull. Its walls consist chiefly of 
three pairs of constrictor muscles, supported by areolar tissue, 
and lined by mucous membrane which is continuous with 
that of the nasal cavities, Eustachian tubes, mouth, larynx 
and oesophagus, with all of which the pharynx communi- 
cates. The portion devoted to the passage of air has its epi- 
thelium columnar and ciliated, while that devoted exclusively 
to the passage of food and drinks has a squamous non-ciliated 
epithelium. Many mucous glands are found in the mucous 
membrane of the pharynx. 

241. The walls of the (Esophagus are composed of three 
coats — muscular, areolar and mucous. The Muscular coat has 
an external layer of longitudinal fibres and an internal layer 
of circular fibres. The fibres are mostly non-striated, ex- 
cepting in the upper part. The Areolar coat is soft and dis- 
tensible, supporting the mucous membrane, which lies in 
folds, so that no opening exists when the oesophagus is not in 
action. Many mucous glands are found, especially at the ends. 

242. The Stomach is the dilated portion of the alimentary 
canal, into which the oesophagus opens from above by the 
cardiac orifice, and the small intestines from below by the 
pyloric orifice. It is a membranous bag, consisting of mucous 



the digestive organs. 



113 



membrane within, serous membrane without, with a muscular 
and areolar layer between. The muscular coat has three 
layers of fibres — longitudinal, circular and oblique. The 
longitudinal are continuous with the longitudinal fibres of 
the oesophagus, and extend divergingly over the body of 
the stomach, collecting into parallel bundles again at the 
intestinal opening, thus continuing into the intestines. The 
circular fibres correspond in arrangement with those of the 
oesophagus, passing in this way around the stomach, till con- 
densed into a sphincter muscle at the pyloric orifice, which it 
partly closes. The oblique muscles are continuous with the 
circular fibres of the oesophagus, from which they spread 
obliquely for a short distance upon the anterior and posterior 
sides of the stomach. 



Fig. 81. 



Fig. 82. 




Mil 



:.- 



y 




ji^ctiif 



Fig. 81 (Leidy). Small Portion of the Mucous Membrane of the Stomach, with 
the Imbedded Gastric Glands. I, The glands. 2, Orifices of the glands. 3, Epithelium 
of the mucous membrane; moderately magnified. 

Fig. 82 {Leidy). Mammilla of the Mucous Membrane of the Stomach, moderately 
magnified, exhibiting the orifices of the gastric glands. 

The areolar coat is united to the muscular by loose areolar 
tissue, but the union is very firm between it and the mucous 
membrane which it supports. The mucous coat has numerous 
blood-vessels and lymphatics, also upright tubular glands, 
secreting the gastric juice, 

10* 



114 ANATOMY, PHYSIOLOGY AND HYGTENE. 

243. The Intestines have their coats and muscular fibres 
arranged like those of the stomach. The areolar coat, with 
its closely-adherent mucous membrane, projects into the in- 
terior of the small intestines, forming valves called vaVvuke 
connivences. These vary in size, some being two inches long, 
and one-third of an inch wide in the middle, tapering at both' 
ends; others are smaller, alternating with the layer. The 
intestinal mucous membrane is covered internally with thread- 
like processes of the membrane, which become erect when 
immersed in water, presenting a velvety appearance, hence 
called villi. 

Fig. 83. 




Fig. 83 (Leidy). Pobtion of the Mucous Membrane from the Ileum, moderately 
magnified, exhibiting the villi on its free surface, and between them the orifices of the 
tubular glands. 1, Portion of an agminated, or clustered gland. 2, A solitary gland. 
3, Fibrous tissue. 

244. The Liver has two coats — the external serous coat, 
formed from the doubling of the peritoneum upon it, and the 
internal areolar coat. Its proper substance is composed of a 
multitude of compressed polyhedral masses, not larger than a 
small pin's head, and named hepatic lobules. Each lobule has 
one part called the base, which rests upon a hepatic vein (333), 
thence called the sub-lobular vein. The impress of the poly- 
gonal base may be seen within when the vein is opened. 
Running longitudinally down the middle of the lobule is a 
vein formed by six or eight veinlets coming from various 
parts of the circumference. This mid-vein, called intralobu- 
lar, unites with the sub-lobular vein at the base of the lobule. 
The lobules are arranged closely side by side, their bases aid- 
ing in the formation of the membranous canals, called the 



THE DIGESTIVE ORGANS. 



115 



portal canal, in which the hepatic vein lies closely adherent 
to the canal-walls. This arrangement resembles that of sessile 
leaves upon the stem. The veinlets of the intra-lobular vein 
originate in a network of veins, upon the lobule-walls, which 
are continuous with the final branches of a small trunk pass- 
ing between the lobules, from the portal vein (333) within 
the poivtal canal. The hepatic system, therefore, is continuous 
with the portal. Each portal vein is always accompanied by 
a hepatic duct and artery, and the three are enveloped in one 
sheath of areolar tissue, which gives off partitions to separate 
the vessels from each other. Outside and beyond these canals, 
this tissue invests the free portion of each lobule, filling the 
inter-spaces. If the other portions could be removed, leaving 
the areolar tissue intact, we should have a perfect areolar 
skeleton of the liver. 




Fig. 84 (Leidy). Inferior Surface of the Liver.— 1, Right lobe. 2, Left lobe. 3, 
Posterior margin. 4, Anterior margin. 5, Quadrate lobe. 6, Caudate lobe. 7, Isthmus, 
or caudate process, connecting the latter with the right lobe. 8, 9, Longitudinal fissure. 
10, Transverse fissure. 11, Portal vein. 12, Hepatic artery. 13, Common biliary duct, 
formed by the union of the hepatic and cystic ducts. 14, Gall-bladder. 15, Inferior cava. 
16, Hepatic veins. 17, Round ligament. 18, Anterior part of the suspensory ligament. 



245. The Spleen has two coats — the outer, serous coat, 
being a reflection of the peritoneum ; the inner, fibro-elastic 



116 ANATOMY, PHYSIOLOGY AND HYGIENE. 

coat, is composed of white fibrous tissue mingled with elastic 
tissue ; when torn, the lacerated surfaces present a deep red- 
dish-brown, pulpy appearance, resembling coagulated blood. 
The particular arrangement and relationship of its constituents 
have not been satisfactorily determined. 

246. The Peritoneum is a serous membrane which invests 
all the abdominal viscera, and is then reflected upon the walls 
of the abdomen. The large doubling of the peritoneum re- 
flected from the front of the vertebral column over the small 
intestine is called the mesentery. 

§21. Chemistry of the Digestive Organs. — Secretions effecting 
Chemical Changes during Digestion. Chemical Character of these Se- 
cretions — Of Saliva — Of the Gastric Juice — Of Bile. Of the Pancreatic 
Juice — Of the Intestinal Juice. Relation of Acids and Alkalies in the 
Digestive Fluids. 

247. The chemical processes concerned in digestion con- 
sist of peculiar reactions between the food and the various 
secretions of the alimentary canal. These fluids are — mucus 
and saliva, secretions of the mucous membrane and glands of 
the mouth ; gastric juice, a secretion of the stomach ; bile, a 
secretion of the liver; pancreatic juice, a secretion of the pan- 
creas ; mucus and intestinal juices, secretions of the mucous 
membrane and glands of the intestines. Each of these fluids 
effects a special change in the constituents of food, till they 
are finally converted from an insoluble to a soluble condition, 
in which they may be absorbed. 

248. Mucus is a colorless and very viscid fluid found upon 
the mucous membrane, and secreted from the plasma of the 
blood by the epithelial cells of that membrane. It is some- 
times alkaline, sometimes acid, but perhaps in its normal 
state, neutral. It is composed chiefly of water, holding from 
four to six per cent, of solids. Its characteristic constituent 
is Mucin (60), also a small amount of extractions, and salts 
like those of the blood. It has limited solvent powers, its 
chief office seeming to be to moisten the food, and thus pre- 
pare it for the action of other digestive fluids. 



THE DIGESTIVE ORGANS. 117 

249. Saliva is a transparent, watery fluid, with a specific 
gravity varying from 1002 to 1008. Its chemical composi- 
tion, as given by Dr. Wright (who has made the salivary 
secretion a special study), is as follows : 

Water 988.10 

Salivin 1.80 

Mucus (and epithelium) 2.60 

Fatty matter .50 

Albumen (with soda)..... 1.70 

Sulpho-cyanide of potassium .90 

Alkaline and earthy salts 3.20 

Loss 1.20 

1000.00 
When first secreted or during secretion, saliva is alkaline; 
in fasting, the moisture of the mouth is nearly neutral, or 
even acid ; but it consists at that time almost entirely of 
mucus. Of salts, the tri-basic phosphate of soda probably 
gives the alkalinity to the secretion. Saliva contains a pecu- 
liar and remarkable salt, sulpho-cyanide of potassium. Be- 
sides, there are found chlorides of sodium and potassium, 
sulphate of soda, phosphates of lime and magnesia, and oxide 
of iron. The " tartar 1 ' of the teeth is formed by these earthy 
salts mixed with mucus, and minute portions of other animal 
matter. The chemical action of saliva is — -first, that of a 
solvent ; it dissolves saline substances, organic acids, alcohols 
and ethers, gum, sugar and the soluble albuminoid and gela- 
tinoid bodies. Second, the saliva converts starch granules 
into dextrine, then into soluble dextrose, glucose, or grape 
sugar. A mixture of all the fluids of the mouth appears to 
form the most active combination for this purpose. 

250. The Gastric Juice is a colorless, or pale-yellow, trans- 
parent, slightly viscid and strongly acid fluid. Its specific 
gravity is 1025. Its composition as given by Schmidt is — 

Water.. 994.4 

Pepsin, with other organic matter 3.2 

Salts 2.2 

Free hydrochloric acid .2 

1000.0 



118 ANATOMY, PHYSIOLOGY AND HYGIENE. 

The small quantity of solid matter (about five per cent.) is 
remarkable, considering its extremely active powers. Pepsin 
is its characteristic constituent (58). The saline matter of the 
gastric juice consists chiefly of alkaline and earthy chlorides 
and phosphates. A small amount of lactic acid is found, but 
whether as a product of secretion or decomposition, is not 
certain. The free hydrochloric acid affords singular example 
of the liberation of a mineral acid from its strongly-combined 
base by an organic process in the animal economy ; the source 
of this acid is probably common salt. Though the most 
powerful solvent known, the gastric juice seems to have no 
effect upon living animal substances ; hence the membranes 
of the stomach remain intact as long as their vital power con- 
tinues. A recent view, founded upon many experiments, attri- 
butes the non-solution to the protecting influence of the blood 
in the capillaries, which is supposed to maintain the alka- 
linity of the tissues — a chemical condition incompatible with 
peptic digestion. Gastric juice changes cane-sugar into glu- 
cose — albuminous substances, as albumen, fibrin, casein, etc., 
into substances called peptones. Gelatinous substances are 
changed chemically by the gastric juice, and lose their 
property of gelatinizing when cold ; but this change is not 
necessary to their solution, which takes place so readily that 
these substances may be taken as food, when albuminous 
substances would remain in the stomach undissolved. 

251. Bile is a somewhat viscid, glutinous and bitter fluid, 
of a dark golden-brown color. Its specific gravity is about 
1026. Its acid (cholic and tauro-cholic) forms four to seven 
per cent, of the secretion, and is always united with soda ; 
the coloring matter forms about five per cent. ; ordinary fats, 
about one per cent. ; salts, one per cent. ; there are also traces 
of choles'terine. Bile is but slightly alkaline, and is some- 
times neutral. It is an important agent in digestion, but its 
action does not depend upon an albuminoid like saliva, pepsin 
or pancreatin. It acts feebly in changing starch into sugar, 
and changes cane-sugar slowly, but grape-sugar rapidly, into 
lactic acid. It dissolves neither albuminoid substances nor 



THE DIGESTIVE ORGANS. 119 

fat, but probably emulsifies the latter. Bile is said to arrest 
the actions of saliva and the gastric juice ; it probably com- 
pletes some particular part of the digestive process, but its 
specific action is not well understood. 

252. The Pancreatic Juice is somewhat viscid, trans- 
parent, colorless and inodorous. Its solid constituents vary 
from L5 to 10 per cent. Its salts are chiefly chloride of 
sodium, and phosphates of lime and magnesia. It is more 
strongly alkaline than saliva ; as digestion goes on, it becomes 
more alkaline and less viscid. Its most peculiar constituent 
is pancreatin, an albuminoid substance whose special com- 
position is not yet determined. This juice is sometimes called 
abdominal saliva ; as it has, like saliva, the power of convert- 
ing starch into dextrine and grape-sugar. It has of itself 
little power over albuminoid and gelatinous substances, but 
is co-operative with the gastric juice. Its chief office seems 
to be to emulsify fatty matters, in which it probably acts 
with the bile. 

253. The composition of Intestinal Juices is not well 
known. They probably differ from common mucus, and 
have special properties. They are colorless, viscid, and con- 
tain from 2 to 3.5 per cent, of solid matter. They appear to 
be alkaline in the ileum, or lower part of the small intestines, 
acid in the ccecum, or beginning of the large intestines, and 
alkaline through the remainder. They convert starch into 
sugar, which in the small intestines passes into lactic and 
butyric acids ; and act still more powerfully upon albuminoid 
substances, and also emulsify fat. 

254. The changes which take place in the three staminal 
principles of food — saccharine, albuminoid and oleaginous sub- 
stances — from their entrance into the mouth till ready for 
absorption, sum up as follows : The conversion of starch com- 
mences with the saliva ; that of albuminoids and cane-sugar 
with the gastric juice ; the emulsifying of fats with the bile 
and pancreatic juice. These processes go on independently 
of each other; the salivary action being unaffected by the 
gastric function, but both aided somewhat by the pancreatic 



120 ANATOMY. PHYSIOLOGY AND HYGIENE. 

juice; the intestinal juice coming in as a general auxiliary 
agent, to complete and harmonize the several operations com- 
menced at different points in the alimentary canal. 

255. It will be noticed in the digestive fluids that there are 
successive alternations of alkali and acid : the saliva being 
alkaline; the gastric juice, acid; the pancreatic juice, bile 
and juice of the ileum, or third part of the small intestine, 
more or less alkaline ; that of the coecum of the large in- 
testine, acid ; that of the remaining portion, alkaline ; — 
alternations giving neutralizations of great importance in the 
chemistry of digestion. 

§ 23. Physiology of the Digestive Organs. — The Assimilation 
of Food. Process by which Food is transformed into Chyle. Destina- 
tion of the Chyle. 

256. Food is necessary to the preservation and growth of 
the body, but it must first be animalized, or assimilated; that 
is, converted into matter having the same characteristics as 
those animal substances into which it is at length to be in- 
corporated. We may include under the term Primary As- 
similation, those animalizing changes necessary to the con- 
version of food into chyle and blood: under Secondary Assimi- 
lation, those necessary to the conversion of blood into integral 
parts of solid tissue. The first series of changes is included in 
the process named Digestion, by which food is transformed 
from its crude state into chyle. 

257. The alimentary canal in which these digestive changes 
take place, is like a long manufacturing establishment, with 
many apartments ; — the first room being the mouth, or mas- 
ticating room, where some of the workmen cut the food ; 
some grind it; some moisten it and supply the needed 
chemicals for making one of the animalizing changes. Masti- 
cation being completed, at the word of command, the obedient 
muscles, with greatest promptness and efficiency, convey the 
food onward to that wonderful laboratory — the stomach. 
The muscles of the soft palate raise the curtain from the base 
of the tongue, and incline it backward, closing the opening 






THE DIGESTIVE ORGANS. 121 

into the nostrils ; those of the small open lid of the trachea, 
the epiglottis, close the lid tightly that the food may pass 
safely over, while the muscles of the tongue, cheeks and floor 
of the mouth, force the food back into the pharynx and the 
oesophagus, the circular muscles of which, by alternate re- 
laxation and contraction, urge it into the stomach. Here the 
food is subjected to a remarkable chemical agent, the Gastric 
Juice, which changes it from a crude state into a soft, homo- 
geneous pulp, called Chyme. 

258. Recent investigations show that this juice is less of a 
"universal solvent" than was formerly supposed — that its 
chemical power is limited to azotized substances ; changing 
albuminoids into albuminose, and gelatinoids into gelatinose, 
the conditions best adapted to assimilation. The change in 
starch which continues in the stomach, is effected by the 
presence of the saliva, which commenced its work in the 
mouth. Oleaginous matters are only reduced to a fine state 
of division and held in suspension by the pulpy chyme. 

During these processes, the mass is undergoing a churning 
or rotary motion, by the joint manipulations of the longi- 
tudinal, circular and oblique muscles, thus bringing part after 
part into the immediate presence of the Gastric Juice. While 
digestion is thus going on, the openings of the stomach are 
well guarded. A return of any part of the mass into the 
oesophagus is prevented by the sphincter muscles near the 
cardiac orifice ; and the passage to the intestines is closed by 
the sphincter muscles of the pyloric orifice, and a valve called 
the pylorus, or " gate-keeper," which, true to its name, stands 
a faithful sentinel till proper chyme presents itself, showing 
evidence of having completed the prescribed curriculum. 
This sentinel-commission seems to last only during the pro- 
cess of digestion, as afterward many substances previously 
detained are allowed free egress. 

259. After passing the pyloric orifice, the chyme is treated 
by other chemical agents — the bile, the pancreatic and intes- 
tinal juices, continuing the chemical processes commenced in 
other parts of the alimentary canal. The fats are reduced to 

n F 



122 ANATOMY, PHYSIOLOGY AND HYGIENE. 

an exceedingly fine state of emulsion, but there is no proof 
of chemical change. The whole pulp is subjected to the con- 
stant wave-like, or peristaltic muscular action of the intes- 
tines, which forces their contents to their respective destina- 
tions. The nutritive portion is called chyle, and is taken up 
by the absorbent vessels and conveyed to the blood ; while 
the innutritious portion is excreted from the system. 

260. The absorbing surface of the intestines is enormously 
increased by the projecting forms and great abundance of the 
villi: they hang out into the nutritious, semi-fluid mass con- 
tained in the cavity of the intestines, as the roots of a tree 
penetrate the soil, imbibing the liquid portions of food with 
wonderful rapidity. 

$23. Hygiene of the Digestive Organs. — Suggestions relative to 
the Preservation of the Teeth — To their Removal. Conditions affecting 
the Quantity of Food demanded by the System. The Quality of Food. 
Directions relating to the Manner of taking Food. Conditions of the 
System requisite for the proper Digestion of Food. 

261. For the Preservation of the Teeth, the first requisite is 
to keep them clean. After meals they should be cleansed, to 
prevent the collection of tartar, and to remove any remain- 
ing particles of food. Such as are inaccessible to the brush, 
may be removed by tooth-picks made of wood, ivory or the 
common goose-quill. Metal injures the enamel. Night and 
morning, the mouth should be cleansed with pure, tepid 
water, after which the teeth should be thoroughly Brushed on 
both surfaces. Occasionally, refined soap may be moderately 
used, if followed by thorough rinsing of the mouth. 

Sudden changes of temperature crack the enamel, hence 
extremes of heat and cold in food and drinks should be 
avoided. Acid and corrosive substances should also be 
avoided, as acidulated drinks and mineral waters, that "set 
the teeth on edge." All tooth-powders containing such 
articles should be banished from the toilet. 

Tobacco contains a "grit" which injures the enamel. It 
also discolors the teeth, debilitates the vessels of the gums, 



THE DIGESTIVE ORGANS. 123 

taints the breath and renders the appearance of the mouth 
forbidding. 

The teeth should be frequently examined, that if enamel 
is removed and decay commenced, they may be filled with 
gold-foil. All amalgams, pastes and cheap patent articles 
should be rejected, both for the sake of the teeth and the 
general* health. 

262. The Removal of the Teeth. The temporary teeth 
should be removed at once, when loose ; or before, if the per- 
manent teeth appear. This is essential to the regularity and 
beauty of the second set. 

Irregular or crowded permanent teeth, generally, require the 
removal of one or more. By pressure upon each other, the 
enamel is injured and the appearance rendered unsightly. 
With a little care the spaces left after extraction will soon be 
filled with the remaining teeth. 

Toothache does not always indicate the necessity of ex- 
traction, as the nerve, or investing membrane, may be dis- 
eased, and the tooth sound. Relief will then be afforded by 
proper medication. 

Observation. — When the removal of a tooth is necessary, 
apply to some skillful operator: something more is needed 
than strong muscles and a pair of forceps. Skill is as requi- 
site in the proper extraction of a tooth, as in the amputation 
of a limb. 

263. The health of the Digestive Organs, in general, re- 
quires the observance of certain conditions relative to their 
natural stimulus — Food. These will be considered under the 
following heads : 1. The Quantity of Food. 2. The Quality 
of Food. 3. The Manner of taking Food. 4. The Proper 
Conditions of the System for receiving Food. 

264. The Quantity of Food necessary to the system 
varies, being affected by age, occupation, temperament, 
habits, temperature, amount of clothing, health and mental 
state. 

265. The supply must equal the waste of the system. In every 
department of nature, waste attends action. The greater the 



124 ANATOMY, PHYSIOLOGY AND HYGIENE. 

amount of exercise, the more rapidly will the particles be 
worn out and removed, and their places need supplying with 
new atoms. 

During the period of growth, the supply must exceed the ivaste, 
for the building of new tissues. This accounts for the keen 
appetite and vigorous digestion in childhood. The same is 
true when persons have become emaciated from famine or 
disease. 

266. When exercise is lessened, the quantity of food should be 
proportionally diminished, otherwise the tone of the digestive 
organs will be impaired, and the health of the system en- 
feebled. This is especially applicable to students, who have 
been accustomed to laborious employments. Self-denial 
should be practiced for a few days, when the real wants of 
the system will generally be manifested by a corresponding 
sensation of hunger. It is a common remark that in semi- 
naries and colleges, students from the country suffer more 
from indigestion and impaired health, than those from the 
cities. 

267. More food is required in winter than in summer; hence, 
by diminishing the amount of food as the warm season ap- 
proaches, the tone of the stomach and vigor of the system 
will be better maintained, thus lessening the liability to 
"summer complaint." In this respect, the lower animals 
seem to learn from instinct, what man is slow to learn from 
reason. 

268. The amount of food should be adapted to the present 
condition of the digestive organs. Imperfectly digested food 
irritates the mucous membrane of the intestines and debili- 
tates the system instead of invigorating it. In sickness, the 
attending physician is the person to decide respecting the 
proper amount. In health, the natural appetite is generally 
a safe guide, as to plain, nutritious food ; but condiments, 
spices, etc., excite a morbid appetite, whose cravings it is un- 
safe to gratify. General languor of the body after meals, 
shows that undue demands are made for an increased supply 
of fluids to enable the overloaded stomach to free itself of its 



THE DIGESTIVE ORGANS. 125 

burden. This, with the extra labor of the secreting glands, 
will soon be followed by debility and consequent inaction. 

269. The Quality of Food should be both nutritive and 
digestible. Substances are nutritions in proportion to their 
capacity to yield the constituents of chyle. Substances are 
digestible in proportion to the facility with which they are 
acted oipon by the digestive fluids. Articles highly nutri- 
tive in themselves, but difficult of digestion, often yield less 
nourishment than those poorer in nutritive quality, but easy 
of digestion. If we confine our diet to easily digested articles, 
the digestive organs will be weakened from want of proper 
exercise; if to highly concentrated diet, they will be injured 
by over-work ; hence, the necessity of choosing, in this respect, 
the " happy medium." 

270. Proper aliment must contain the three staminal prin- 
ciples of food. These are albuminous, oleaginous and saccha- 
rine substances ; the first contain carbon, oxygen, hydrogen 
and nitrogen ; the last two are destitute of nitrogen. Various 
experiments have shown that if we feed upon any one of 
these groups, to the exclusion of the other two, or upon any 
two to the exclusion of the third, the health will be impaired. 
Milk contains all the food principles ; — the albuminous, being 
furnished by its caseine ; the oily, by the butter ; and the 
saccharine, by the sugar of milk. Beef is rich in fat and 
albumen, and also contains inosit, or muscle sugar. Most of 
the cereals contain gluten (an albuminoid), starch, sugar and 
oil. Wheat, however, has the first three constituents without 
the oil. It is most nutritious in the form of " Graham flour ;" 
by rejecting the bran, most of the gluten is lost. Eggs are 
very rich in albumen, and the yolk also contains oil. Beans, 
peas, etc. afford starch and much legumine (an albuminoid). 
Potatoes abound in starch. Sago, tapioca, rice, arrow-root, 
etc., are constituted almost wholly of starch. These articles 
or their substitutes, properly combined, will yield the neces- 
sary elements to the system. 

271. Food shoidd be properly cooked. However nutritious 
an article of food may be, if not well cooked, it is not only 

11* 



126 ANATOMY, PHYSIOLOGY AND HYGIENE. 

unsavory to the palate, but hurtful to the digestive organs. 
The simplest methods of preparation by cooking are the best. 
Meat should be broiled, roasted, or made into soup. Fried 
meats are apt to be indigestible and also less nutritious. 
The fat used in frying is infiltrated by the heat and usually 
penetrates the whole mass. It is mistaken economy to fry 
meats for the laboring class ; better throw the fresh steak 
upon coals, and add simply salt and pepper, than to deluge 
it in boiling fat. Much of the nutriment of beef when salted, 
is extracted by the brine ; and during the process of boiling, 
still another portion remains in the boiling water, thus leaving 
but little more than hardened muscular fibre to grace the 
platter. (The liquor of boiled beef may be converted into 
soup.) The breakfast "hash" is too frequently unfit to be 
eaten by the student or sedentary person, from want of being 
well cooked. 

The cooking of vegetables should be thorough and com- 
plete. The proper combination and cooking of a few articles 
of food (as flour, milk, eggs and butter), require skill, which 
in reality, assumes the importance of no inferior art. 

272. The Quality of Food should be adapted to the season and 
climate. Highly stimulating food may be used almost with 
impunity during the cold season of a cold climate ; but in the 
warm season and in a warm climate it is very injurious. 
Animal food being more stimulating than vegetable, is there- 
fore well adapted to winter, and vegetable to spring and 
summer. Where the digestive organs are weakened or dis- 
eased, it is very important that a nutritious vegetable diet be 
adopted as the warm season approaches. 

273. 'Vegetable diet is most suitable for children. The organs 
of a child are more sensitive and excitable than those of an 
adult; hence, stimulants of every kind should be strictly 
avoided, and the food mainly of a vegetable character. In 
this "fast age," this is a suggestion of vast importance. 
Parents mourn over many evil effects of unrestrained passion 
and moral deterioration in the rising generation, while in 
truth, these are too often but the legitimate harvest of the 



THE DIGESTIVE ORGANS. 127 

seed they have themselves sown in the form of stimulating 
food and drinks. The old spelling-book assertion, that 
"Bread and milk is the best food for children" is as true 
now, as it was in the days of our fathers. 

274. Some temperaments require more stimulating food 
than others. As a general rule, persons of obtuse sensations, 
and slpw movements, are benefited by animal or stimulating 
food ; while individuals of highly sensitive constitutions, and 
quick, hurried movements, require a nutritious and unstimu- 
lating vegetable diet. 

275. The Manner of taking Food exercises a control- 
ling influence upon the health of the digestive organs. 

276. Food should be properly masticated. This is essential 
to secure the fine division necessary to the proper action of 
the gastric juice and other fluids, and especially to mix the 
food with the requisite amount of saliva. Rapid eating 
should be avoided, not only as a violation of good table man- 
ners, but as a violation of the laws of our physical nature, 
whose penalty, in the form of dyspepsia with its numerous 
train of evils, will sooner or later be visited upon the trans- 
gressor. 

277. Drink should not be taken with the food. Nature sup- 
plies the appropriate moisture, and if tea, coffee, or any other 
fluid be used as a substitute, indigestion will follow, from the 
absence of the necessary amount of saliva. Again, drinks 
taken into the stomach must be absorbed before the digestion 
of other articles is commenced. Thirst between the meals 
does not always arise from a demand of the system for fluids, 
but may be induced by fever or local disease of the parts 
connected with the throat. This may often be relieved by 
chewing a cracker, or some other dry substance, thus exciting 
the salivary glands. This is a safe resort when thirst accom- 
panies a heated condition of the system, arising from over- 
exercise ; while the practice of taking cold fluids is dangerous 
and should never be indulged. 

278. Regard should be paid to the temperature of food and 
drink. Hot food or drink, for a short time unduly stimu- 



128 ANATOMY, PHYSIOLOGY AND HYGIENE. 

lates the vessels of the mucous membrane of the gums, mouth 
and stomach ; then reaction follows, bringing loss of tone and 
debility of these parts. This practice is a fruitful cause of 
spongy gums, decayed teeth, sore mouth and indigestion. 
On the other hand, if food or drink be taken too cold, an 
undue amount of heat is abstracted from the stomach, this 
arrests the digestive process, and thus deranges the system. 

279. Food should be taken at regidar and suitable periods. 
The interval between the meals should be regulated by the 
character of the food, and the age, health, exercise and habits 
of the individual. In the young, the active, and the vigorous, 
food is more rapidly digested than in the aged, the indolent 
and the feeble; consequently, it should be taken more fre- 
quently by the former class than by the latter. The average 
time required to digest an ordinary meal is from two to four 
hours. The stomach should always have from one to three 
hours of rest, before the next meal. Eating between meals, 
is a habit ruinous to the digestive organs, inasmuch as the 
chemical processes are by this means disturbed, and the 
stomach given no time for rest. 

280. The Conditions of the System for receiving 
Food, are of practical importance for the healthy action of 
the digestive process. 

281. Food shoidd not be taken immediately before or after 
severe exercise of body or mind. The functional exercise of 
any organ abstracts fluids, sanguineous and nervous, from 
other parts of the body, thus weakening those parts for the 
time. Severe exercise of muscle, concentrates the forces in 
the muscle ; severe exercise of the brain, concentrates the 
forces in the brain ; the same is true of the vocal and other 
organs. After severe exercise, from thirty to forty minutes 
should be allowed before eating, for restoring equilibrium to 
the system. The student, farmer or mechanic, who hurries 
from his toil to his dinner to " save time,'' will, in the end, 
lose more time than he saves. After eating, the digestive 
organs need, for a time, the chief use of the vital forces, and 
if they are habitually expended elsewhere, as in study or 



THE DIGESTIVE ORGANS. 129 

labor, digestion will be arrested, the chyle cheated of its 
proper elements, and headache, dullness and general derange- 
ment will follow. A moderate exercise of the muscles, a 
social chat and a hearty laugh, aid digestion, and tend " to 
shake the cobwebs from the brain. " These directions are 
particularly applicable to the ambitious student who feels 
that he must "save time" and "must have the lesson." Let 
him try the experiment, and he will soon find that in the 
after-dinner hour, his lesson is better learned when he spends 
half the hour in recreation, and the other half in close appli- 
cation. Many students are obliged to give up their course 
of study, from simple neglect of these rules. 

Observation. — The same principle will apply to lower ani- 
mals. They will perform more labor by having a suitable 
period of repose after being fed. Two dogs were fed upon 
the same kind of food, one was kept quiet, the other sent in 
pursuit of game. In an hour both were killed. In the 
stomach of the quiet dog, digestion was nearly complete; in 
that of the other, the food was scarcely altered. 

282. Persons should abstain from eating at least three hours 
before retiring for sleep. It is no unusual occurrence for those 
persons who have eaten heartily immediately before retiring 
to have unpleasant dreams, or to be aroused from their un- 
quiet slumber by colic pains. In such instances, the brain 
becomes partially dormant, not imparting to the digestive 
organs the requisite amount of nervous influence ; this being 
deficient, the unchanged food remains in the stomach, causing 
irritation of this organ. A healthy farmer who was in the 
habit of eating a quarter of a mince pie just before retiring, 
became annoyed with unpleasant dreams, and among the 
images of his fancy, he saw that of his deceased father. 
Becoming alarmed, he consulted a physician, who, after a 
patient hearing, advised the patient to eat half a mince pie, 
assuring him that then he would see his grandfather. 

283. The mental state exerts an influence upon the digestive 
process. This is clearly exhibited when an individual re- 
ceives sad intelligence. Let him be sitting at a plentiful 

F* 



130 ANATOMY, PHYSIOLOGY AND HYGIENE. 

board with a keen appetite, and the unexpected news destroys 
it, because the excited brain withholds the stimulus ; hence 
all unpleasant themes, labored discussions, or matters of busi- 
ness, should be banished from the table. Light conversa- 
tion, enlivening wit and cheerful humor wonderfully promote 
digestion. 

Indigestion arising from nervous prostration should be treated 
with great care. The food should be simple, nutritious, 
properly cooked, moderate in quantity and taken at regular 
periods. Large quantities of stimulating food, frequently 
taken, serve to increase the nervous prostration. Exercise 
in the open air, and a cheerful state of mind, are very bene- 
ficial in restoring the natural, healthy action of the brain, 
and thus aiding the digestive powers. 

284. After long abstinence, unstimulating food should be 
taken, and in small quantities. As in case of sickness, when 
the appetite begins to return, the nurse must use much dis- 
cretion, and the patient, often, self-denial. The popular adage, 
" that food never does harm, when there is a desire for it," is 
untrue. Too frequently, when a patient satisfies his cravings, 
it is to induce relapse into the former disease, and at the risk 
of life. The digestive organs are weak, and must be gradually 
brought into action. It is often better to give the food in a 
solid, rather than liquid form, so that the salivary and mucous 
glands may be stimulated to action. 

285. The condition of the shin exercises an important in- 
fluence upon digestion. Let free perspiration be checked, 
either from uncleanliness, chills or any other cause, and the 
functional action of the stomach is diminished. This is one 
of the fruitful causes of "liver and stomach complaints" 
among the filthy and half-clad inhabitants of our cities and 
villages. Attention to bathing and clothing would prevent 
many " season complaints," especially among children. 

286. Pure air is necessary to give a keen appetite and vigorous 
digestion. The digestive organs must have a plentiful supply 
of pure blood, and to have pure blood we should breathe 
pure air. Poor ventilation is a frequent cause of indigestion. 



THE DIGESTIVE ORGANS. 131 

Persons who sleep in ill-ventilated rooms have little or no 
appetite in the morning. A manufacturer stated before a 
committee of the British Parliament, that he had removed an 
arrangement for ventilating his mill, as he noticed that his 
men ate much more after his mill was ventilated than before, 
and he could not afford to have them breathe the pure air. 
Compression of the vital organs prevents the introduction of 
a sufficient supply of pure air, and is one of the causes of 
dyspepsia now so prevalent among ladies. 

General Observations. — All aliment is separated into nutri- 
ment and residuum. The latter should be regularly expelled 
from the system, otherwise headache, dizziness and general 
uneasiness will ensue, and if allowed to continue, the founda- 
tion will be laid for a long period of suffering and disease. 
For the preservation of health, there should be in most per- 
sons a daily evacuation of residual matter. Evening is the 
best time, especially is this true when persons are afflicted 
with piles. Constipation may, in many cases, be relieved 
by friction over the abdominal organs, and by making 
an effort to evacuate the residuum at some stated period 
each day. 

Eecapitulation. — Digestion is most perfect when the 
action of the cutaneous vessels is energetic; the brain 
moderately stimulated; the blood well purified; the mus- 
cular system duly exercised ; the food properly cooked and 
masticated, taken at regular periods, and adapted in quality 
and quantity to the present condition of the individual. 



?. 24. Comparative Splanchnology. — Nutritive Apparatus of Verte- 
brates. Compare the Mouths and Teeth of Vertebrates. — The Digestive 
Fluids. — The Stomach and Intestines. 

287. In the Nutritive Apparatus of all vertebrates, 
as in the Motory, a general plan of parts obtains, subject to 
the variations required to preserve the harmony of relation 
between the organization and the use to which it is to be 
applied. 



132 



288. In no part do we find a greater variety or a nicer 
accommodation to particular wants than in the Mouths 
and Teeth of different animals. In Mammals, the project- 
ing jaws, the wide mouth, the strong, pointed, sharp, ena- 
meled edges of the teeth enable carnivorous, or flesh-eating 
animals, to seize and hold their prey, and the hinge-like 
movement of the jaw, to divide it like a pair of scissors; as seen 
in the cat and the lion. The full lips, the rough tongue, the 
furrowed, cartilaginous palate, the broad, rough surface of 
the teeth, the central plates of enamel and the lateral move- 
ment of the jaw, qualify the herbivorous, or grain-eating ani- 
mals, for grazing, and grinding their food, as the grain is 
crushed between the upper and nether mill-stone ; as the 
sheep and the horse. The elongated, tapering muzzle, the 



Fig. 85. 



Fig. 86. 




Fig. 85 represents the Teeth of Carnivora, or Flesh-Eating Animals. 
Fig. 86 represents the Teeth of Insectivora, or Insect-Eating Animals. 



cone-pointed, enameled molars locking into the enameled de- 
pressions of the opposite jaw, enable the insectivorous animals 
to burrow in the earth, for the insects and worms upon which 
they feed, and also to crush them ; as in the mole and hedge- 
hog. The two chisel-shaped incisors, enameled only in front, 
allowing more rapid w 7 ear of the posterior than the anterior 
part, keeping them always sharp ; the bag of pulp at the 
base of these teeth, providing for growth equal to the wear at 
the top ; the backward and forward movement of the jaws ; 



THE DIGESTIVE ORGANS. 133 

and the great size and strength of the lower jaw, adapt the 
rodentia, or gnawers, to their mode of life ; as in the rat and 
the squirrel. 

Fig. 87. 




Fig. 87. Lower Jaw of a Squirrel. — 1, The enamel of the gnawing tooth. 2, The 
ivory. 3, The lateral furrows of the molar teeth. 

289. In Birds the mouth receives a new character, both in 
substance and in form. Instead of fleshy lips and teeth of 
enameled bone, we have the hard and hffny investment of 
the jaws, known as the bill, destitute of true teeth. This 
organ varies in size and form, according to the food of the 
species, which may be grains, insects, fishes or flesh. 

290. Reptiles swallow their food without mastication, hence, 
their jaws and throats are made capable of great dilatation, 
and their teeth, used only for seizing and retaining their prey, 
all resemble each other. 

291. The jaws of most Fishes are armed with teeth, and in 
many cases these are placed in all parts of the mouth, and 
even in the gullet. 

292. In most animals, the digestive fluids are supplied by 
mucous follicles and glands, similar to the salivary glands in 
man. The simpler the function of the mouth, the smaller 
and simpler the arrangement for the supply of these fluids, 
as is seen in birds, also in reptiles, and some fishes that swal- 
low their food without mastication, and have no organ of 
secretion but the liver. 

293. The Stomach and Intestines of vertebrates vary in 
size, form and relative length. They are simpler, smaller 
and shorter in carnivorous than in herbivorous or granivorous 

12 



134 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



animals ; while the ox has intestines about twenty times the 
length of his body, those of the lion are but three or four 
times its own length. 



Fig. 88. 



Fig. 89. 




Fig. 88. Stomach of the Sheep. — 1, The oesophagus. 2, The rumen. 3, The reticulum. 
4, The omasum. 5, The abomasum, or rennet. 6, The intestine. 

Fig. 89. Stomach of an Ox.— 1, The onsophagus. 2, The rumen (paunch). 3. The 
reticulum (honeycomb). 4, The omasum (many-plies). 5, The abomasum (rennet). 6, 
The intestine. 



294. Ruminants, as the sheep and ox, have a stomach with 
four cavities. The first stomach, called the Ru'men, or 
"Paunch;" the second, the Reticulum, or "Honeycomb ;" the 
third, the Oma'sum, or "Many-Plies;" the fourth, the Ab r oma- 
sum, or "Rennet :" the latter, taken from the young calf, is 
used in cheese-making. 

The food when first swallowed is received into the Rumen, 
where it accumulates while the animal is feeding. Here it is 
moistened by the fluids secreted by the walls of this cavity. 
It then passes into the Reticulum, where it receives addi- 
tional secretions, and is made into little pellets, or " cuds," 
which, when the animal is at rest, are returned to the mouth, 
to be re-chewed and mixed with the saliva. This pulp passes 
directly into the third cavity, to be prepared for the fourth, 
where true digestion takes place. It is then received by the 
intestinal canal. 



THE DIGESTIVE ORGANS. 
Fig. 90. Fig. 91. 



135 




Fig. 90. The Alimentary Canal of Man.— ], (Esophagus. 2, The stomach. 3, Car- 
diac orifice. 11, Pylorus. 5, Biliary duct. 4, 4, 4, 4, Small intestines. 6, Pancreatic 
duct. 7, Ascending colon. 8, Transverse colon. 9, Descending colon. 10, Rectum. 

Fig. 91. The Alimentary Canal of a Fowl.— 1, The oesophagus. 2, Ingluvies (crop). 
3, Proventiculus (secreting stomach). 4, Triturating stomach (gizzard). 5, Intestine. 
6, Two caeca. 



136 ANATOMY, PHYSIOLOGY AND HYGIENE. 

Fig. 92. Fig. 93. 





Fig. 92. The Alimentary Canal of the Flying Lizard.— 1, The oesophagus. 2, The 
stomach. 3, 3, Small intestine. 4, Large intestine. 

Fig. 93. The Alimentary Canal of the SwoRD-Fisn.— 1, Liver. 2, 3, Caucus, or 
pouches, connecting with small intestine. 4, 5, Small intestine, coiled. 6, Large intes- 
tine. 7, Biliary duct. 



295. In Birds there are usually three cavities, or stomachs ; 
the first is a dilatation of the oesophagus, called the Crop, or 
" Inghivies" where the food is macerated and softened; the 
second is the true stomach, named "Proventidulus" where the 
mucous membrane is provided with mucous follicles, secreting 
an acid which acts still farther upon the food ; and the third 
is the Gizzard, or Triturating cavity. The latter, in graniv- 
orous birds, has immense strength, being composed of mus- 
cular fibres running in different directions, and lined with a 
horny membrane. Gravel and angular stones are instinctively 



THE DIGESTIVE ORGANS. 



137 



swallowed to assist in the grinding process. In flesh-eating 
birds the gizzard is thin and membranous. 

296. In Reptiles the alimentary canal differs much from 
that of mammals or birds. As a general rule, it is shorter 
in proportion to the trunk than in warm-blooded vertebrates. 
The transition from the oesophagus to the stomach is by a 
pouch-like enlargement ; the small intestines usually have a 
few coils ; the large intestines in most reptiles are short, 
simple and straight, without csecal appendage at its begin- 
ning. The liver is relatively large. 

297. In Fishes' the alimentary canal is more diversified in 
length, size and form than in reptiles ; the oesophagus is a 
short and funnel-shaped canal ; the stomach is shaped either 
like a syphon or a pouch (cseca). In some species of fish, 
the small intestines extend in a line from the stomach to 
their termination ; in others, there are found from two to 
eight coils. The large intestines are short and straight. 
The liver is usually large, with numerous appendages. In 
the cod it is soft and saturated with oil, which is expressed 
for medicinal purposes. 

Fig. 94. 




Fig. 94. The Alimentary Canal of the Herring.-!, (Esophagus. 2, Stomach. 
3, 3, 3, 3, Small intestine. 4, Caeca. 5, Air-bladder. 7, Pneumatic duct. 
12 * 



CHAPTER VII. 

ABSORPTION. 

298. We have observed the changes in food till its forma- 
tion into chyle — changes which have taken place in the ali- 
mentary canal, and which are included under the general 
term, Digestion. The chyle, however, is virtually external to 
the animal body. The process by which it is conveyed 
within is called Absorption; and the vessels conveying it are 
named Absorbents. 

The term absorption, used in its largest sense, however, 
includes more than the mere taking up of nutrient material 
from the alimentary canal. It embraces that general pro- 
cess by which all external soluble substances, whether solid, 
liquid or gaseous, beneficial or poisonous, nutrient, stimulant 
or respiratory, are introduced into the tissues of the body. 
It also comprehends, in part at least, the process by which 
portions of the living tissues are themselves removed, or ab- 
sorbed within the body. The former may be called General 
Absorption, and the latter, Intrinsic, or Interstitial Absorption. 

\ 35. Anatomy of the Absorbents. — The Process of Absorption — 
Specific and General. The Absorbent Vessels. Lymph. Distribution 
of the Lymphatics. The Thoracic Duct. The Lymphatic Duct. Posi- 
tion of Lymphatic Glands. Absorbent Veins. 

299. The absorbents consist of certain blood-vessels, espe- 
cially the venous capillaries, and the absorbents proper, viz., 
Lymphatic* Vessels and Glands. 

The fluid conveyed by the lymphatic absorbents is a trans- 
parent, transuded portion of the blood, called Lymph. The 
lymphatic vessels of the small intestines are named Lac'teals^ 

* Lat., lympha, water. f Lat., lac, milk. 

138 



ABSORPTION. 
Fig. 95. 



139 




Fig. 95. A Representation of the Lymphatic Vessels and Glands. — 1,2, 3,4,5,6, 
The lymphatic vessels and glands of the lower limbs. 7, Lymphatic glands. 8, The com- 
mencement of the thoracic duct. 9, The lymphatics of the kidney. 10, Of the stomach. 
11, Of the liver. 12, 12, Of the lungs. 13, 14, 15, The lymphatics and glands of the arm. 
16, 17, 18, Of the face and neck. 19, 20, Large veins. 21, The thoracic duct. 



140 ANATOMY, PHYSIOLOGY AND HYGIENE. 

from their milky appearance during active digestion, when 
they are filled with chyle. In the interval of digestion, they 
convey lymph like the other lymphatics. 

300. The Lymphatic Glands through which the vessels 
pass are somewhat hard, pinkish bodies, varying in size from 
that of a hemp-seed to that of a large pea. 

301. The Lymphatic Vessels are distributed through 
most of the system. Few are found in the muscles, and none 
in the brain or spinal cord, though they doubtless exist there. 
They abound in the secreting membranes, especially in the 
skin and the mucous membrane. 

The finer lymphatics unite into trunks, which either accom- 
pany the blood-vessels and form the deep lymphatics, or run 
on the surface of organs or in the sub-areolar tissue, forming 
superficial lymphatics. From all parts of the body, these 
trunks run toward the root of the neck and unite in two 
main trunks which end in the venous system, viz., the Tho- 
racic and Lymphatic Ducts. 

The lymphatics of the lower limbs of the abdomen, of the 
left side of the head and neck, and of the left upper limb, 
form the Thoracic Duct; those of the right side of the head 
and neck, and right upper limb, form the Lymphatic Duct. 

302. The Thoracic Duct commences with a dilatation, 
named the " Receptaculum Chyli," or receptacle of the chyle. 
This vessel is formed by the convergence of lymphatics from 
the lower extremities, the intestines, stomach, spleen, pan- 
creas, kidneys and the greater part of the liver. The " recep- 
taculum chyli" is usually placed upon the second lumbar 
vertebra, a little to the right of the aorta (329). It soon 
passes behind the arch of that vessel, crossing over the oeso- 
phagus, and ascends on the left side to the root of the neck, 
where it curves downward and outward behind the great 
blood-vessels, and finally opens into the angle at the junction 
of two large veins (330). 

303. The Lymphatic Duct is about an inch long, and 
has a similar termination on the right side of the body. 

304. The lymphatic glands are found in the axilla of the 



ABSORPTION. 



141 



Fig. 96. 




Fig. 96 (Ltidy). View of the Great Lym- 
phatic Trunks.— 1, 2, Thoracic duct. 4, The 
right lymphatic duct. 5, Lymphatics of the 
thigh. 6, Iliac lymphatics* 7, Lumber lym- 
phatics. 8, Intercostal lymphatics, a, Supe- 
rior cava, b. Left innominate vein, c, Eight 
innominate vein, d, Aorta, e, Inferior cava. 



arm (arm-pit) and in the 
groins ; chains of glands are 
found on each side of the 
neck; a few in the arm ; also 
many about the bronchi, or 
air-tubes ; and in the pelvis 
or abdomen ; — those of the 
lacteals being abundant in 
the Mes'entery* 

305. The veins of the in- 
testines acting as absorbents 
unite with those coming from 
the stomach, the spleen and 
the pancreas, thus forming 
the Portal vein, which enters 
the liver through a fissure in 
the concave surface. 

I 26. Histology of the Ab- 
sorbents. — Histology of the 
Lymphatic Vessels — Glands. 
Origin of the Lymphatics. 

306. Most of the Lym- 
phatic Vessels are long, 
thread-like, transparent tubes, 
with coats so exceedingly deli- 
cate that their structure is a 
matter of inference from that 
of the Thoracic Duct, which 
has three coats, like the veins. 
The external coat is the 
thickest, and consists of white 
fibrous tissue, with longitudi- 
nal webs of elastic tissue ; the 
middle coat consists of un- 
striated muscular, elastic and 
connective tissues ; the inter- 



* Gr. ; mesos, middle, and enteron, the intestine. 



142 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



nal coat, of a lining epithelium, an elastic basement mem- 
brane, supported by longitudinal laminae of elastic tissue. 
The larger lymphatic tubes are liberally supplied with valves 
formed by the infolding of the inner coat. These valves are 
arranged in pairs, and are much more numerous in the 
smaller than in the larger vessels. In the thoracic duct, they 
are sometimes more than an inch apart. A very strong pair 
is placed at the opening of the thoracic duct into the large 
veins. 

Fig. 97. Fig. 98. Fig. 99. 




Fig. 97. A Single Lymphatic Vessel, much magnified. 

Fig. 98. The Valves of a lymphatic trunk. 

Fig. 99. 1, A Lymphatic Gland, with several vessels passing through it. 



307. The Lymphatic Glands are not well understood. 
They seem to be composed of a large number of vesicles, or 
pouches, which communicate with each other and also with 
the lymphatic tubes. The tubes, or vessels, entering the 
gland, are called afferent vessels, and those emerging from it, 
efferent vessels. Each vesicle of the gland seems to connect 
with an afferent and an efferent vessel. 

308. The lymphatics are of such tenuity and transparency, 
it is with the greatest difficulty that they can be discovered, 



ABSORPTION. 143 

hence, their origin is imperfectly known. They appear to 
originate in a capillary network among the sanguiferous 
capillaries, but not to communicate with them. The lacteals 
originate in the villi of the intestines, and unite more and 
more till their entrance into the receptaculum chyli. 

309. The Lymph consists of a fluid part containing nuclei, 
minute^ granules, and sometimes a few oily globules. 

£ 27. Chemistry of the Absorbents. — Chemical Changes in the 
Absorbent System — In the Portal Circulation. 

310. We know little of the chemical changes which take 
place in the absorbent system ; but the chyle drawn from the 
large absorbent trunks near their entrance into the "recepta- 
culum chyli" is very different from that just absorbed by the 
lacteals. During its passage through these vessels and their 
glands it undergoes important alterations, assimilating it to 
the blood. 

311. The following table, by Carpenter, gives the relative 
proportions of the three chief ingredients of the chyle in 
different parts of the absorbent system. 

In the afferent lacteals, from the intestines to the mesen- 
teric glands : 

Fat in maximum quantity (numerous fat or oil -globules). 
Albumen in medium quantity. 
Chyle-corpuscles, few or none. 
Fibrin almost entirely wanting. 

In the efferent lacteals, from the mesenteric gland to the 
Thoracic Duct : 

Fat in medium quantity. 

Albumen in maximum quantity. 

Chyle-corpuscles very numerous, but imperfectly developed. 

Fibrin in medium quantity. 

In the Thoracic Duct : 

Fat in minimum quantity (few or no oil -globules). 
Albumen in medium quantity. 

Chyle-corpuscles numerous, and more distinctly cellular. 
Fibrin in maximum quantity. 



144 ANATOMY, PHYSIOLOGY AND HYGIENE. 

312. In the portal circulation, soon after the absorbed sub- 
stances are introduced into the blood, and come in contact 
with its organic ingredients, they become converted into 
other substances; the albuminose is in part changed into 
blood-albumen, a substance very different from albuminose 
or the original albumen. There is also probably some fibrin, 
while the sugar rapidly decomposes, losing its characteristic 
properties. The contents of the portal vein undergo changes 
in the liver before being taken up by the hepatic vein, but 
these are not well understood; arriving at the entrance of 
the general circulation, these newly-absorbed ingredients 
have already become measurably assimilated to those pre- 
viously existing in the blood. 

§ 28. Physiology of the Absorbents. — Office of the Lymphatics. 

Absorbent Power of Different Tissues. Absorption in cases of Disease. 
Imbibition of Animal Membranes. 

313. It was formerly supposed that the office of the Lym- 
phatics was excretive — that of conveying from the system 
portions of waste matter no longer of use ; but as these ves- 
sels are found to commence most frequently in tissues where 
nutritive changes are few — as there is a conformity in the 
nature of the fluids, chyle and lymph, the chief difference 
being due to the presence of fat, and a large proportion of 
albumen in the chyle — as the two fluids are conveyed into 
the general current of circulation, just before the blood is 
again transmitted into the system at large — the almost in- 
evitable inference is, that lymph, like chyle, is a nutritious 
fluid. There is much evidence that the lymph is obtained 
from the blood, and it is not improbable that the lymphatics 
take up those crude materials which were absorbed directly 
by the veins and subject them to an assimilating agency, 
resembling that acting upon the nutritive substances in the 
lacteals. 

314. The office of the lymphatics may also include an- 
other, assimilation. Disintegration of the tissues is every- 
where taking place. Every respiration, every heart-beat, every 



ABSORPTION. 145 

muscular movement, every thought, is produced at the ex- 
pense of the life of some of the tissues ; but, says Carpenter, 
" The death of the tissues by no means involves their imme- 
diate and complete destruction; and there seems no more 
reason why an animal should not derive support from its 
own dead past, than the dead body of another individual. 
Whilst, therefore, the matter that has undergone too com- 
plete a disintegration to be again employed as nutrient mate- 
rial is carried off by the excretory process, that portion which 
is capable of being again assimilated may be taken up by 
the lymphatic system." This whole lymphatic system may 
be looked upon as one great assimilating or blood-making 
gland. 

315. Different membranes have different absorbent powers, 
and the power of the same membrane varies with change of 
condition. The most active is the mucous membrane ; thus, 
in the alimentary canal, it takes up a large portion of the 
food ; in the lungs it absorbs gases in a state of solution. In 
this way are introduced into the system miasmatic and con- 
tagious exhalations. Fine, solid particles are sometimes ab- 
sorbed, as arsenic. Instances of poisoning are not uncommon 
among manufacturers of artificial flowers and green paper- 
hangings, arsenite of copper or " Scheele's green" being em- 
ployed in the coloring. 

316. Though much impeded by the cuticle, absorption 
takes place to a considerable extent through the skin, and 
the use of medicinal baths is based on this fact; shipwrecked 
sailors, destitute of fresh water, find that thirst is relieved by 
immersing the body in salt water. Life is sometimes sup- 
ported for a time by immersing the patient in baths of milk 
or broth. 

317. In serous and synovial membranes, the fluids poured 
out into the joint in rheumatism and other inflammations are 
absorbed. Absorption is shown in areolar tissue, as in taking 
up dropsical fluids ; also by sub-cutaneous injections of a solu- 
tion of morphia, to relieve suffering from neuralgic pain, from 
severe operations, obstinate cough and other irritations. 

13 G 



146 ANATOMY, PHYSIOLOGY AND HYGIENE. 

Observations. — 1st, In cases of disease, where no food is 
taken into the stomach, life is maintained by the absorption 
of fat. In consumption, even the muscles and more solid 
parts of the body are absorbed. 2d, Animals living in a 
half-torpid state during winter, derive their nourishment 
from the same source. 

318. There are no visible openings in the membranes for 
the passage of these absorbable substances, but their entrance 
seems to be effected by a peculiar action of animal mem- 
branes which enables certain fluids to pass directly through 
them by a kind of imbibition, a process called endosmdsis* 

§ 29. Hygiene of the Absorbents. — Conditions of Air affecting 
Absorption. Effect of Nutritious Food. Effect of the Removal of the 
Cuticle. 

319. The air should be as free as possible from impure vapors 
and gases; hence the importance of thorough ventilation, 
especially in the sleeping-room, since exhalations from the 
system are greater at night than by day. 

Observation. — In infectious diseases, the impure air should 
be constantly carried from the room, and the nurse should be 
careful to avoid the infected air, approaching the patient on 
the side in which the currents of air are admitted. 

320. Moisture increases the activity of the absorbents; hence, 
persons living in marshy districts contract miasmatic and 
contagious diseases more readily than those living in a drier 
atmosphere. In such localities the house should be plenti- 
fully supplied with fresh air, and kept dry by the use of fires. 
Especially is this necessary morning and evening, in spring 
and autumn, and often in summer. 

Observation. — For the above reason, the air of the sick- 
room should be kept dry, otherwise the poisonous exhalations 
are absorbed by the lungs and skin, both of the patient and 
of the nurse. 

321. Nutritious food lessens the activity of the absorbents ; 

* Gr., endonj within, and osmos, impulse. 



ABSORPTION. 147 

hence, in cases of infectious diseases, due attention should be 
given to the food of the attendants and of the family. Some 
persons use alcoholic stimulants or tobacco, " to prevent 
taking disease," but these increase the activity of the ab- 
sorbents, and the liability to contract disease. A moderate 
amount of nutritious food will be more efficacious. 

322.»i?i handling poisons, care should be taken that the cuticle 
be unbroken, as absorption is very rapid when the skin is 
removed. In contagious diseases, if the skin is broken, it 
should be covered with adhesive plaster while at work over 
the patient. In handling dead bodies, it is well to lubricate 
the hands with olive-oil or lard. The absorption of poisonous 
matter through a slight "scratch" or puncture of the cuticle, 
as the removal of a " hang nail," has cost several valuable 
lives. 



PAROTID GLAND •--:'A7m° uc ^ 



EXTERNAL JUGULAR VEIN- 

INTERNAL JUGULAR VEIN— 

CLAVICLE 



BRKHmLr n $iN. 



MD1AL rST;. 




Fig. 100 



CHAPTER VIII. 

THE CIRCULATION. 

\ 30. The Blood. Composition of the Blood. Relation of the Absorbent 
System to the Blood. 

323. As the contents of the absorbent vessels enter the 
blood-vessels, they undergo their last complete change into 
that remarkable fluid, the blood, which contains all the mate- 
rials for the support of every part of the animal fabric. 

The blood consists of a liquid portion named liquor san- 
guinis, the plasma, or liquor of the blood, which holds in sus- 
pension multitudes of minute, circular bodies, called blood- 
corpuscles; these are of two kinds, the white, or colorless, 
and the red ; the latter are so minute that no less than one 
hundred millions are said to exist in a single drop of blood ; 
the red color is due to their accumulation, as, when in thin 
layers, they appear yellowish. They contain only a slightly 
colored fluid, while the white corpuscles have, in addition, a 
nucleus and indistinct granules. 

324. The blood is constantly undergoing loss, from supply- 
ing material for the secretions, for nutritive changes in the 
solid tissues, and also in the blood itself. 

Observation. — The French call blood " chair coulant," run- 
ning flesh, and with reason, since it not only contains the 
same constituents as flesh, but one-fifth of its weight is solid 
matter. 

325. In order that this blood with its cargo of supplies 
should fulfill its mission of nutrition, it must be kept con- 
stantly moving in a circuit, including every part of the body; 
this movement is called its Circulation, which takes place 
through the Heart and the Blood-vessels, which consist of the 
Arteries, Capillaries and Veins. 

13* 149 



150 ANATOMY, PHYSIOLOGY AND HYGIENE. 

I 31. Anatomy of the Circulatory Organs.— Construction of the 
Heart. The Arteries, Veins and Capillaries, and their Relation to each 
other. The Aorta and its Divisions. Arrangement of the Veins. 

326. The Heart is a hollow muscle enclosed in a sac, 
named Pericardium* In the male its proportion to the 
body is about 1 to 169 ; in the female, about 1 to 149. The 
heart is cone-like in shape, whence its triple division into 
base, body and apex. Its length is about five inches, and its 
basal diameter about four inches. It is everywhere free or 
unattached excepting at the base, which by means of the 
large blood-vessels is joined to the vertebral column, reach- 
ing from the region of the fourth dorsal vertebra to the 
eighth. The apex is directed downward, forward and to the 
left, pointing to the junction of the fifth rib with its cartilage. 
The interior of the heart is divided by a longitudinal mus- 
cular septum, or wall, into two chambers, named the right 
and the left chamber; each of these is divided by a trans- 
verse constriction into two apartments, named the Auriclef 
and the Ven'tricle ; the auricle occupying the basal end of 
the organ, and the ventricles the body and apex. There are 
virtually two hearts placed side by side, having no communi- 
cation with each other and differing in function. The right 
division is sometimes called the pulmonic heart, and the left 
the systemic heart. 

327. The Arteries are firm, membranous, cylindrical 
tubes, arising from the ventricles of the heart by two trunks; 
that from the left ventricle, named the Aorta, is the systemic 
trunk ; and that from the right ventricle, named the Pul- 
monic artery, is the pulmonic trunk. 

The systemic trunk, or aorta, divides and subdivides into 
finer and finer arteries, like the branches from the trunk 
of a tree, excepting that these branches communicate with 
each other in a finer network, till the ultimate ramifications, 
too minute to be seen by the naked eye, extend to every 

* Gr., peri, about, and kardia, heart. f Lat., auris, an ear. 



THE CIRCULATION. 



151 



nook and corner and atom of the body. These final branches 
are called Capillaries. 

The Capillaries serve to connect the terminations of the 
arteries with the beginning of the veins, so that it is impos- 
sible to tell just where the artery ends, and the vein begins. 

Fig. 102. 





Fig. 101. A Front View of the Heart. — 1, Tlie right auricle of the heart. 2, The 
left auricle. 3, The right veutricle. 4, The left ventricle. 5, 6, 7, 8, 9, 10, Vessels 
through which the blood passes to and from the heart. 

Fig. 102. A Back View of thf, Heart. — 1, The right auricle. 2, The left auricle. 3, 
The right ventricle. 4, The left ventricle. 5, 6, 7, The vessels that carry the biood to 
and from the heart. 9, 10, 11, The vessels of the heart. 



328. The Veins thus commencing with the capillaries 
unite into larger and larger veins, converging toward the 
heart, like the branches of a tree toward its trunk, till the 
final union in two trunks (the ascending and descending 
Venae Cavse), that connect with the right auricle of the 
heart. The aorta and cavse constitute the large vessels of 
the Systemic, or general circulation. The Pulmonic, or 
lesser circulation from the right ventricle through the lungs 
to the left auricle, has a similar set of vessels ; the trunk 
leaving the right ventricle is named the Pulmonic artery, and 
corresponds to the aorta ; those trunks conveying the blood 
to the left auricle and corresponding to the vense cavse, are 
named the Pulmonary veins. 



152 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 103. 




Fig. 103 (Leidy). The Aorta.— 1, Arch of 
the aorta. 2, Thoracic aorta. 3, AbdomiDal 
aorta. 4, Innominate artery. 5, Right com- 
mon carotid. 6, Right subclavian. 7, Left 
common carotid. 8, Left subclavian. 9, Bron- 
chial artery, a small branch of the aorta. 10, 
(Esophageal arteries. 11, Intercostal arteries 
of the right side ; 12, of the left side. 15, 
Coronary artery. 16, Splenic artery. 17, 
Hepatic artery. 18, Superior mesenteric 
artery. 19, Supra-renal arteries. 21, Infe- 
rior mesenteric artery. 22, Lumbar arteries. 
23, Common iliac arteries. 24, Middle sacral 
artery, a, Aortic orifice of the diaphragm. 
b, Articulation of the head of the ribs, c, 
Anterior scalene muscle. 



329. The Aorta springs 
from the left ventricle of the 
heart, is about an inch in 
diameter, and is the main 
trunk of the arterial system, 
supplying pure blood to 
every part of the body. It 
is divided into the arch, 
the thoracic and abdominal 
aorta. The Arch ascends 
from the heart, slightly in- 
clines toward the right side, 
curves obliquely backward 
to the left side, and descends 
to the left side of the third 
dorsal vertebra, where it be- 
comes the Thoracic Aorta. 
The arch gives off main 
branches as follows : the 
right and left Coronary ar- 
teries, whose branches ramify 
upon the walls of the heart ; 
the three trunks going to the 
head and upper extremities ; 
viz., the right Carotid and 
right Subclavian and the In- 
nominata trunk, which soon 
divides into the left Carotid 
and left Subclavian arteries. 

330. The Thoracic Aorta 
commencing with the termi- 
nation of the arch, descends 
at the left of the vertebral 
column, gradually inclining 
toward the median line, 
which it nearly reaches oppo- 
site the last dorsal vertebra, 



THE CIRCULATION. 153 

where it passes through the diaphragm and becomes the 
abdominal aorta. The thoracic division gives off branches 
to the lungs, pericardium, oesophagus, lymphatic glands, the 
intercostal, pectoral and serrated muscles, also those of the 
back. 

331. The Abdominal Aorta inclines a little to the left, 
gives pff branches to the liver, stomach, spleen, pancreas, 
kidneys and to the abdominal muscles. Opposite the fourth 
lumbar vertebra, it divides into two large trunks, called the 
common Iliacs. These subdivide into two branches, called 
the external and internal Iliac arteries. The continuation 
of the external iliac when it reaches the groin, is named the 
Femoral artery, which passes down the groove of the thigh 
between the extensor and adductor muscles ; after passing 
through the tendon of the great adductor muscle it is called 
the Popliteal artery, which divides into the anterior and pos- 
terior tibial arteries, the latter providing the fibular artery 
and various branches sent to several parts of the foot 
and toes. 

332. The carotid arteries are divided into two branches, 
the external and the internal ; the former giving off branches 
to the face and head, excepting the brain and orbits, which 
are supplied by the latter. The subclavian arteries furnish 
branches to the brain, spinal cord and membranes, the ears, 
pleura, and various muscles of the back and neck. The 
extension of the subclavian artery is called the brachial in 
the inner and fore part of the arm ; the two main branches 
of the brachial extending down the fore-arm are named 
the radial, at the anterior and outer part of the fore-arm, 
and the ulna, situated at the anterior and inner part of the 
fore-arm. The radial artery toward the wrist runs near the 
surface, being covered only by the fascia and skin. We 
learn the condition of the general circulation by its throb- 
bings, which we call the pulse. The radial and ulnar 
arteries divide and subdivide into the various carpal, pal- 
mar and digital ramifications, supplying the wrist, hand 
and fingers. 

G* 



154 ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 104. 




Fig. 104 (Leidy). Left Common Carotid dividing into the External and Internal 
Carotid Arteries. — 1, Common carotid artery. 2, Internal carotid. 3, External carotid. 
4, Superior thyroid. 5, Lingual. 6, Pharyngeal artery. 7. Facial. 8, Inferior palatine 
and tonsillar arteries. 9, Submaxillary. 10, Submental. 11, Occipital. 12, Posterior 
auricular. 13, Parotid branches. 14, Internal maxillary. 15, Temporal artery. 16, 
Subclavian artery. 17, Axillary. 18, Vertebral artery. 19, Thyroid axis. 20, Inferior 
thyroid giving off the ascending cervical. 21, Transverse cervical. 22, Supra-scapular. 
23, Internal mammary artery. 



333. The Veins are arranged in two sets — the superficial 
and the deep-seated ; the former lie immediately under the 
skin, possessing no corresponding arteries ; the deep-seated 
veins directly attend the arteries, and usually take the 
same name. The largest arteries have one venous trunk; 
the medium-sized have two, called vence comites. The veins 
unite into eight trunks with their branches; the coronary 
vein receives the blood from the walls of the heart, and con- 
veys it to the right auricle ; the Superior Vena Cava derives 



THE CIRCULATION. 



155 



its branches from the head, 
neck, upper extremities and 
walls of the thorax. It termi- 
nates at the upper back part 
of the right auricle of the 
heart. 

The Inferior Vena Cava col- 
lects the blood from the lower 
extremities, pelvis and abdo- 
men, and terminates in the 
right auricle. 

The Portal vein is a short 
trunk about three inches in 
length, derived from the con- 
vergence of the veins of the 
stomach, spleen, pancreas and 
intestines ; this passes into the 
liver, where it divides and 
subdivides, being distributed 
throughout the organ. This 
blood, with that of the hepatic 
artery, is returned to the gene- 
ral circulation by the hepatic 
veins (244). 

The Pulmonary veins are 
four in number, two for each 
lung. They commence with 
the capillaries of the lungs, 
and converge till a single trunk 
is formed for each lobe, or 
three trunks for the right lung 
and two for the left; but the 
trunk from the middle lobe of 
the right lung joins that from 
the upper lobe of the same 
side, and the four mouths dis- 
charge into the four angles of 





Fig. 105 {Leidy). Veins of the Thorax 
and Abdomen — 1, Inferior cava. 2, right, 
3, Left renal veins. 4, Superior cava. 5, 
Right, 6, Left innominate veins. 7, In- 
ternal veins. 8, External jugular veins. 
9, Subclavian vein. 10, Azygos vein. 



156 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



the left auricle. The pulmonary veins perform the function 
of arteries, as they convey pure blood. 



Fig. 106. 




Fig. 106 (Leidy). The Portal System of Veins. — a, Portal vein, b, Splenic vein. 
c, Right gastro-epiploic vein, d, Inferior mesenteric vein, e, Superior mesenteric vein. 
f, Trunk of the superior mesenteric artery. 1, Liver. 2, Stomach. 3, Spleen. 4, Pan- 
creas. 5, Duodenum. 6, Ascending colon : the transverse colon is removed. 7, Small 
intestine. 8, Descending colon. 



? 33. Histology of the Circulatory Organs.— The Pericardium 
and Endocardium. The Valves of the Heart. The Muscular Struc- 
ture of the Heart. The Coats of the Arteries — Of the Veins — Of the 
Capillaries. 

334. The Pericardium, or heart-case, is composed of two 
layers, one fibrous, and the other serous. The fibrous layer 
forms a loose sac over the heart, being connected only at the 



THE CIRCULATION. 



157 



base, from which it embraces the several blood-vessels and 
becomes continuous with their external coats. The serous 
layer closely invests the heart and also the great blood-ves- 
sels at its base, from which it is reflected to line the fibrous 
layer of the pericardium. 



Fig. 1( 



Fig. 107. 





Fig. 107. Diagram of the Heart, with its Investment.— 1, 1, Right and left auricles. 
2, 2, Right and left ventricles. 3, 4, Pericardium. 5, Pulmonary artery. 6, Aorta. 

Fig. 108. Diagram of the Heart and Valves. — 1, Descending vena cava (vein). 2, 
Ascending vena cava (vein). 3, Right auricle. 4, Opening between the right auricle 
and the right ventricle. 5, Right ventricle. 6, Tricuspid valves. 7, Pulmonary artery. 
8, 8, Branches of the pulmonary artery that pass to the right and left lung. 9, Semi- 
lunar valves of the pulmonary artery. 10, Septum between the two ventricles of the 
heart. 11, 11, Pulmonary veins. 12, Left auricle. 13, Opening between the left auricle 
and ventricle. 14, Left ventricle. 15, Mitral valves. 16, 16, Aorta. 17, Semilunar 
valves of the aorta. 

335. The Endocardium, or lining membrane of the heart, 
is a thin, translucent membrane continuous with the inner 
coats of the blood-vessels. It consists of an epithelium, an 
exceedingly thin basement membrane and a fibro-elastic layer 
closely adherent to the general muscular structure beneath. 
At the opening between the auricles and ventricles, at the 
commencement of the aorta and of the pulmonary artery, 
the fibro-elastic tissue forms four rings, sometimes called 
fibrous zones. It also forms valves by its little folds, en- 
closing muscular fibres. Those at the openings of the aorta 
and the pulmonary artery are named, from their shape, Semi- 

14 



158 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



lunar valves. They form complete pockets, three in number, 
and have a triangular arrangement about the orifices. Be- 
hind each of these valves is a cavity, or pouch, in the artery. 
336. Between the auricles and ventricles are valves also 
formed by foldings of the endocardium. On the left side are 
two, named Mitral valves. They form a kind of curtain, from 
whose floating edge small white cords (chordae tendinse) pass 
to some of the columnar carna3, thus preventing the edge 
from being carried into the auricle. On the right side are 
three valves formed of three folds of membrane, called the 
Bicuspid valves. 



Fig. 109. 



Fig. 110. 




Fig. 109. Spiral and involuted arrangement of the fibres of the heart. 
Fig. 110. Gyration of the fibres of the heart at the apex. 

337. The muscular structure of the heart is based upon the 
four fibrous zones, which furnish a point of departure for 
most of the muscular fibres in the ventricles. Those of the 
auricles and of the ventricles are quite independent of each 
other. The crossing fibres form networks arranged in three 
circular lamina?, the superficial, middle and internal. The 
superficial fibres commence at the base, and pursue a spiral 
course to the apex ; those of the right side, running from 
right to left ; those of the left side, from left to right. These 
two spiral sets encircle the apex and cross each other some- 
what like the lines in the figure 8, thus forming a remark- 



THE CIRCULATION. 159 

able whorl, called the vortex. They do not stop here, but 
pass inward and turn upward to the auriculo-ventricular 
fibrous rings from whence they started, forming the deep- 
seated layer, or the true walls of the ventricles with their 
fleshy columns ; hence the deep-seated and superficial layers 
are continuous muscles. Between these two layers is the 
middle stratum of fibres, more or less circular, forming a 
truncated cone, with its base corresponding to the auriculo- 
ventricular orifice. 

338. The muscular fibres of the auricles consist of a super- 
ficial set investing the anterior portion of both auricles, and a 
deep-seated layer which in the left auricle constitutes a network 
of circular and oblique fibres, all traceable to the auriculo- 
ventricular orifice, around which they form sphincter muscles. 
The corresponding fibres of the right auricle intersect each 
other, and are traceable to the corresponding orifice. 

339. The Arteries have comparatively thick walls, com- 
posed of three coats continuous with the endocardium and 
the fibrous coat of the pericardium. The external coat is 
chiefly of white fibrous tissue, with the spiral fibres crossing 
each other from opposite sides of the vessel. This coat is 
quite thin in the aorta and larger trunks ; it forms about 
half the thickness of the walls in the medium-sized vessels, 
and disappears entirely in the smaller vessels. The middle 
coat is thick in the large arteries, and gradually becomes 
thinner till its disappearance before reaching the capillaries. 
This coat is, in the large trunks, chiefly composed of elastic 
tissue with some muscular fibres ; in the smaller vessels, of 
muscular tissue with few elastic fibres. The inner coat is 
thinnest and most elastic; like the endocardium, it has an 
epithelium, a basement membrane and a layer of connective 
elastic tissue. The latter is intimately connected with the 
middle coat. 

340. The Veins are constructed, in general, like the ar- 
teries, but their coats are much thinner. Many of the larger 
veins, particularly in the limbs, have crescent-shaped valves, 
usually arranged in pairs and opposite each other. These are 



160 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



formed by the doublings of the lining membrane, strengthened 
with intervening fibro-elastic tissue. Behind each valve there 
is a dilatation of the vein, forming a little pouch. The pul- 
monary veins have no valves ; the same is true of the venae 
cavse, the portal vein and its branches, the hepaticse, renal 
and spinal veins, and most of those of the head and neck ; 
they are more abundant in the lower than in the upper ex- 
tremities. The walls of both arteries and veins are furnished 
with nutritive vessels and with nerves. 




Fig. Ill (Leidy). Diagrams exhibiting the Arrangement of the Valves of Veins. 
— A, Vein laid open, showing the valves in pairs. B, Longitudinal section of a vein, in- 
dicating the mode in which the valves, by apposition of their free edges, close its calibre. 
The dilated condition of the walls behind the valves is also seen. C, Vein distended, 
showing how the sinuses behind the valves become dilated. 

341. The Capillaries are exceedingly delicate tubes, 
which are continuous with the basement membrane of the in- 
ternal coat of the arteries and veins. The network of the 
capillaries varies, adapting itself to the particular tissue in 
which it is found ; thus, in the lungs it takes the form of the 
air-cells ; in the muscles the meshes are elongated. 



\ 33. Chemistry of the Blood. — Analysis of the Blood. Relative 
Proportions of Different Chemical Substances in the Corpuscle and the 
Plasma. 

342. The analysis of blood by different chemists gives very 
different results, due chiefly to the variable composition of 



THE CIRCULATION. 161 

this fluid under different conditions connected with health, 
age, temperament, etc. The following table from Lehman 
shows the composition of 1000 parts of blood, calculated from 
the analysis of venous blood by Lecanu : 

Corpuscle. Plasma. Total. 

Water 344.000 451.45 795.45 

Hsematin 8.375 8.375 

Globulin 141.11 141.11 

Fat 1.155 .86 2.015 

Extractive matter 1.3 1.97 3.27 

Salts 4.06 4.275 8.335 

Fibrin 2.025 2.025 

Albumen 39.42 39.42 

500.000 500.000 1000.000 

343. According to this estimate, blood contains about 
eighty per cent, water and twenty per cent, solid matter. In 
round numbers, of the 205 solid parts, 156 belong to the red 
and white corpuscle, and 141 are globulin (modified albu- 
men), 8} parts hsematin ; the red coloring substance, 1 part 
fat, H extractive matters, and 4 parts salts, chiefly salts of 
potash. The remaining 49 parts of solids belong to the 
liquor sanguinis, or fluid portion of the blood, and include 
rather more than 2 parts blood-fibrin ; the rest of these solids 
are proper to the serum of the blood, and consist of 39 J parts 
of albumen, 1 fat, 2 extractive matters, and 4J salts, chiefly 
soda. 

344. Other mineral substances are found in small quan- 
tities. The distribution of mineral substances in the blood is 
peculiar. Thus, the red corpuscles contain ten times as much 
potassium as the liquor sanguinis, but only one-third as much 
sodium ; the corpuscles contain five times as much phosphoric 
acid as the liquor sanguinis, but only about half as much 
chloride. The chloride of sodium (common salt) is, there- 
fore, chiefly contained in the fluid plasma of the blood, and 
the phosphoric acid principally, and the potassium almost 
entirely, in the corpuscles, which also contain a large share 
of the fatty matters. 

14* 



162 ANATOMY, PHYSIOLOGY AND HYGIENE. 

Blood charged with gases, especially oxygen, nitrogen and 
carbonic acid, has a saline taste, and is an alkaline fluid. 
When blood is exposed to the air, the fibrin coagulates, 
carrying down with it mechanically the corpuscle; this 
leaves an amber-like fluid, called serum, in which the clot 
floats. 

£ 34. Physiology of the Circulatory Organs. — Necessity for 
Circulation — For the Double System of Circulation. Plan of Systemic 
Circulation — Of Pulmonic Circulation — Their Relation to Each Other. 
Provisions necessary in a Circulatory Apparatus. The Circulatory Im- 
pulse. Prevention of a Re-flow. Additional Forces for maintaining 
the Current in the Arteries — In the Veins. Equalization of the Current. 
Supply of a due Proportion to each Organ. Provision for Contingencies. 
The Mechanism of the Body Compared with Works of Art. 

345. The tissues are so constructed that their vitality de- 
pends upon their activity, and their activity upon the amount 
of oxygen and nutritive material supplied ; the oxygen being 
essential to the chemical combinations, without which there 
could be no new deposit of tissue particles, and also to fur- 
nish a stimulus, especially to the nervo-muscular system ; 
and the nutritive matter being necessary to supply the waste 
produced by these chemical and vital activities. Hence, the 
necessity of a pneumatic apparatus for providing a constant 
and sufficient supply of oxygen ; and of a hydraulic appa- 
ratus for conveying the prepared nutriment to every atom 
of the body, and also to remove the waste, worn-out particles. 
The former need is met by the exquisite mechanism of the 
lungs, and the latter by the no less refined mechanism of the 
heart and blood-vessels. The two apparatuses are brought 
into use and harmonious co-working, by the double circulation 
of the blood, hence the necessity of the double heart. 

346. From the left ventricle the blood is forced into the 
aorta, to be diffused through the arteries to the capillaries 
in every part of the body; thence it is returned by the veins, 
through the vense cavse, to the right auricle, which delivers 
it to the right ventricle ; this completes the Systemic Circu- 
lation. From the right ventricle it is thrown into the pul- 



THE CIRCULATION. 



163 



monary artery, and through its branches to the pulmonary 
capillaries, thence, returned by the pulmonary veins, which 
coalesce into four trunks, and finally enter the left auricle, 
which immediately pours it into the left ventricle. This 
completes the lesser, or Pulmonic Circulation, and the two 
constitute one complete circuit of the double circulation. 



Fig. 112. 



Fig. 113. 





Fig. 112. A Diagram.— 1, Left ventricle of the heart. 2, 3, Aorta. 5, 5, Arteries that 
extend to the lower extremities. 6, 6, Arteries of the neck. 7, 7, Arteries of the arms. 

Fig. 113. A Diagram. — 1, Right auricle of the heart. 2, 3, Large veins that open into 
the right auricle. 4, 4, Veins of the lower extremities. 5, 5, Veins of the arms. 6, Veins 
of the neck. The arrows show the direction that the blood flows. 



164 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



347. Both circulations are carried on at the same time, 
that is, the auricles contract and dilate simultaneously ; the 
same is true of the ventricles, whose action immediately fol- 
lows that of the auricles. Hence, at the same instant, by 
the action of the ventricles, pure blood is thrown into the 
body, and impure blood into the lungs ; and at the same in- 
stant, the auricles receive impure blood from the body, and 
pure blood from the lungs. 



Fig. 114. 



Fig. 115. 





Fig. 114. A Diagram.— 1. Left auricle. 2, Right auricle. 3, Left ventricle. 4, Right 
ventricle. 5, 5, Pulmonary artery. 6, Trachea. 

Fig. 115. A Diagram.— 1, Right auricle. 2, Left auricle. 3, Right ventricle. 4, Left 
ventricle. 5, 5, Right and left pulmonary veins. 6, Trachea. 

348. How to construct and keep in successful operation an 
apparatus which should secure the free circulation of the 
blood, was no easy mechanical problem. It was necessary 
to provide the requisite motor-power at the starting-point; 
to prevent a backward flow ; to protect the arteries against 
the force of the heart ; to maintain a ceaseless current ; to 
equalize the pressure, especially in the capillaries ; to ensure 
the proper relative quantity of blood to each organ ; and to 
provide for contingencies arising from accident, or other ab- 
normal action. 

349. For giving the proper circulatory impulses, we find 
in each heart, instead of a single cavity, the auricle and 
ventricle affording a far more powerful impulse. The auricle 



THE CIRCULATION. 165 

is gradually filled by steady streams from the veins, hence 
the contraction and consequent force is moderate ; but as the 
ventricle receives the whole quantity at once, there is a sud- 
den energetic contraction or jerk, hence, a powerful thrusting 
of the blood into the aorta and pulmonary artery. Also the 
peculiar spiral and circular arrangement of the muscular 
fibres of the ventricles is most effective in producing the 
greatest projectile force. Here comes in a beautiful example 
of the adaptation of each part to its destined use. The walls 
are much thinner in the auricles than in the ventricles ; and 
of the two ventricles, they are thinner in the right than in 
the left, inasmuch as the right sends the blood only to the 
surrounding lungs, the left, to the remotest part of the body. 
The power and the required impulse exactly correspond. 

350. Though the arrangement of fibres in the heart is such 
as to give the blood a decidedly forward impulse, yet the 
danger of a backward flow is evident. This movement is 
prevented in the auricles, by the contraction of the muscular 
fibres about the mouths of the veins ; by the contraction of 
the vein-walls ; and also in the right auricle, by valves in the 
mouths of the inferior vena cava and the cardiac sinus, and 
by the valves in the veins at the base of the neck. The re- 
flow from the ventricles is prevented by the mitral or bicuspid 
valves of the systemic heart, and by the tricuspid valves of 
the pulmonic heart. By the contraction of the muscular 
columns of the ventricles, the chordce tendince, or little cords 
of the valves, are stretched, bringing the delicate membranes 
together and into the ventricle, thus effecting a closure. The 
reflux from the aorta and the pulmonary artery is obviated 
by the semi-lunar valves. The slightest re-flow fills the little 
pouches behind the valves, thus closing them till the next 
contraction of the ventricle. The valves of the right side are 
more delicate than those of the left, their strength and form 
being, in each case, exactly adapted to their specific work. 

351. The arteries are protected against the sudden action 
of the heart, by the elastic fibres of their middle coat, which 
yield easily, thus preventing the liability to rupture. 



166 ANATOMY, PHYSIOLOGY AND HYGIENE. 

352. The maintenance of the circulatory current, though 
largely due to the original impulse of the heart, or the " vis 
a tergo" is aided in various ways. The smooth, glassy sur- 
face of the inner arterial coat lessens the friction ; the recoil 
of the elastic fibres of the middle coat after distension, and 
the contraction of the muscular fibres of the same coat, urge 
the blood forward. These fibres increase in number, accord- 
ing to the distance from the heart. The respiratory move- 
ments also aid the arterial flow. 

353. The capillaries have probably no contractility, and 
though the heart-impulse may be sufficient to inject the blood 
into them, it can hardly effect the passage through. Hence 
other means are employed. We think the following physical 
principle, as applied by Prof. Draper, will account for the 
capillary circulation. If two liquids communicating with 
one another in a tube, have for that tube different chemical 
affinities, movements will ensue, and that liquid having the 
strongest affinity grill move most rapidly, often driving the 
other liquid before it. Now, these are the exact conditions 
in the capillaries of the systemic circulation ; the arterial 
blood, as it contains oxygen, with which it is ready to part 
and take in exchange carbonic acid which the tissues set 
free, must have a greater affinity for these tissues than has 
the venous blood in which these changes have already taken 
place. Hence, the arterial blood entering at one end of the 
capillaries must drive before it, and expel at the other end, 
the blood which has become venous in passing through them. 
The same principle holds in the pulmonic circulation, but the 
affinities are opposite. The venous blood has a strong affinity 
for the oxygen in the air-cells of the lungs, and contains car- 
bonic acid which it is ready to give up ; hence, the exchange 
takes place, and the arterialized blood, having no longer an 
affinity for the air, is driven by the venous blood, and thus 
the circulation goes on as long as the blood continues to be 
aerated. 

The portal current is accounted for in the same way. The 
bile-secreting cells of the liver are made up of materials con- 



THE CIRCULATION. - 167 

veyed by the portal veins and capillaries, and hence have an 
affinity for them. The supply having been deposited and 
the affinity thus destroyed, the fluid will be driven into the 
hepatic capillaries, thus maintaining the portal current. 

354. The flow through the veins is continued by the com- 
bined action of several forces; viz., the capillary impulse; 
the suction-power of the dilating auricles, drawing the blood 
to the "heart, or the " vis a fronte ;" the presence of valves, 
single in the small veins, double in the larger trunks, and 
sometimes composed of three flaps ; and the thoracic respira- 
tory movements. 

355. The intermittent pressure caused by the action of the 
heart is equalized by the frequent branching and the anas- 
tomosing of the arteries as they approach the organs to which 
they are distributed, since the more points of entrance, the 
less will be the pressure ; and by the elastic coat of the ar- 
teries, whose after-distension gradually converts the separate 
impulses into a continuous motion, otherwise the capillaries 
of many delicate structures would doubtless be ruptured. 
We And the elastic tissue most abundant in the vessels near 
the heart, just where it is most needed. 

356. The proper relative amount of blood is secured to 
each organ primarily by the adaptation of its main artery, 
and it is interesting to notice how the size of the artery every- 
where corresponds to the need of the organ. Again, the 
calibre of the arteries is susceptible of variation within cer- 
tain limits ; hence, the supply of blood to any organ may be 
in some measure regulated by the contractility of its arteries, 
which is itself controlled by the nervous system. 

357. Contingencies are also provided for, by the frequent 
anastomoses of the arteries, by their capability of distension, 
and also by their capability of positive enlargement by the 
increased nutrition of their walls. Hence, though obstruc- 
tions should exist in some part, the organ may be measurably 
supplied with blood. 

358. Though our knowledge is so imperfect, our tracing 
so indistinct, our souls must be dead indeed if they do not 



168 ANATOMY, PHYSIOLOGY AND HYGIENE. 

respond to the exclamation of him of old, " I am fearfully 
and wonderfully made" — fearfully, for often, as in the heart- 
valves, there is but a gossamer web, a tendinous cord, be- 
tween the life here and the life beyond : wonderfully, for in 
all the round of human arts, we find nothing which can at 
all compare, in perfect simplicity, in faultless skill, in match- 
less beauty, in the refinements of philosophy and in the 
subtleties of chemistry, with this vital workmanship, which 
can be none other than that of God. Till we reach our 
utmost range of vision, it is ever the same unfolding of the 
care, the wisdom, the benevolence of Him to whom nothing 
is great and nothing small ; and beyond our finiteness, His 
eye alone surveys the work of busy legions of artificers, ever 
building up what the wear and tear of life is ever breaking 
down ; His ear alone listens to the music of the million life- 
rills, as they murmur on in their ever-ceaseless flow. 

§ 35. Hygiene of the Circulatory Organs. — Conditions favoring 
Free Circulation. Treatment of Divided Arteries. 

359. A natural and equal temperature should be preserved. 
The blood-vessels are contracted by cold, hence, a chill in 
any part of the body drives the blood to other parts. The 
chilled part is thus weakened, while the over-burdened parts 
suffer from congestion. If the surface is chilled, the blood 
is thrown upon the internal vital organs, hence the necessity 
of warm clothing, and also frequent bathing, which favors 
the free action of the cutaneous vessels. 

360. The clothing should be loosely worn. Compression of 
any kind impedes free circulation. Pressure about the vital 
organs is especially injurious. Ligatures used to retain in 
place any article of apparel should be elastic. Tight dress- 
ing Of the neck deprives the brain of its due amount of blood, 
and retards the free return of venous blood from this organ ; 
an item of particular importance to students, public speakers 
and persons predisposed to apoplexy or any brain disease. 

361. Exercise promotes the circulation of the blood. By the 
action of the muscles, the blood is propelled more rapidly 



THE CIRCULATION. 



169 



through the blood-vessels, thus promoting a vigorous circula- 
tion in the extremities and skin. The best stimulants for a 
pale skin and cold extremities are a union of vigorous mus- 
cular exercise with agreeable mental action, and systematic 
bathing attended by thorough friction. 

362. The quality and quantity of the blood modify the action 
of the heart and blood-vessels. If this fluid is abundant and 
pure, the circulatory vessels act with more energy than when 
it is deficient in quantity or defective in quality. 

Illustrations. — 1st, If blood in large quantities is drawE 
from the veins of an athletic man, the heart will beat feebly 
and the pulse become weak. 2d, A similar effect is pro- 
duced when the blood becomes vitiated by the inhalation of 
impure air. 

Fig. 116. 




Fig. 116. The Manner of Compressing Divided Arteries. — A, Compressing the large 
artery of the arm with the thumb. B, The subclavian artery. C, Compressing the 
divided extremity of an artery in the wound with a finger. 

363. Hemorrhage from divided arteries should be arrested, 
15 H 



170 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



otherwise the heart soon ceases its action, and the person 
faints. If a large artery be wounded, every beat of the pulse 
throws out the blood in jerks. Until surgical help can be 
summoned, the flow of blood may be stopped either by com- 
pressing the vessel between the wound and the heart, or by 
compressing the end of the artery next the heart in the 

wound. 

Fig. 117. Fig. lis. 




Fig. 117. The Method of Applying the Knotted Handkerchief, to compress a 
divided artery. A, B, Track of the brachial artery. 

Fig. 118. A, C, The track of the femoral artery ; the compress applied near the groin. 

After compression as described and illustrated, take a 
square piece of cloth, or handkerchief, twist it cornerwise, 
and tie a hard knot in the middle. Place the knot over the 
artery between the wound and the heart, carry the ends 
around the limb and tie loosely. Place a stick under the 
handkerchief near the last tie, and twist till the fingers can 
be removed from the compression without a return of the 
bleeding. When an artery in a limb be cut, elevate the 
limb as far as possible, till the bleeding ceases. 

364. In flesh wounds, when no large vessel is divided, wash 
the parts w T ith cold w T ater, and when bleeding has ceased, 
draw T the incision together, and retain it with strips of ad- 
hesive plaster, not more than a quarter of an inch in width. 
Then apply a loose bandage, and avoid all ointments, " heal- 



THE CIRCULATION. 



171 



ing salves" and washes. In removing the dressing from the 
wound, both ends of the plaster should be raised and drawn 
toward the incision. To lessen the liability of a reopening, 
a proper position for the union should be regarded. If the 
wound be between the knee and ankle, and on the anterior 
part, extend the knee and bend up the ankle ; if on the pos- 
terior j>art, reverse the movement, and, in general, suit the 
position to the case. 

Fig. 119. 




"Fig. 119 represents the Manner of applying adhesive strips to wounds. 



Observation. — The union of the divided parts is effected by 
the action of the blood-vessels, and not by salves or ointments. 
The only object of the dressing is to keep the parts together 
and protect the wound from air and impurities. Nature per- 
forms her own cure. Such wounds seldom need a second 
dressing, and should not be opened till the incisions are 
healed. 

Fig. 120. 




Fig. 120. a, a. Representation of Wounds on the back part of the arm and fore-arm. 
6, b, Wounds of the anterior part of the arm and fore-arm. By bending the elbow and 
wrist, the incisions at a, a, are opened, while those at 6, b, are closed. Were the arm ex- 
tended at the elbow and wrist, the wounds at a, a, would be closed, and those at b, b, 
would be opened. 

Wounds made by blunt instruments do not admit of direct 



172 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



and immediate union. In these oases, a soothing poultice, 
as of linseed-meal, may be applied, and the limb should be 
kept still. A physician should be consulted, as dangerous 
diseases may be induced by such wounds. Wounds from 
poisonous bites may be treated at first by suction, either by 
cupping-glasses or the mouth, thus preventing the absorption 
of the poisonous matter into the system. When this is 
effected, cover the wound with a poultice, as one made of 
ground slippery-elm bark. 

Observation. — Although animal poisons, when introduced 
into the circulatory fluid through the broken surface of the 
skin, frequently cause death, yet they can be taken into the 
mouth and stomach with impunity, if the mucous membrane 
lining those parts is unbroken. 



I 36. Comparative Angiology. — The Composition and Circulation 
of the Blood of other Mammals, of Birds, of Reptiles and of Fishes, as 
compared with the same in Man. 

365. In most Mammals, the blood is similar to that of man, 
but the largest animals, as the elephant, have very small 
corpuscles. All mammals have four cavities in the heart, 
as in man. Its form, however, is more rounded and less 
elongated. The heart in quadrupeds lies on the median line 
of the body, and not a little to the left of it, as in man. 
There is a marked peculiarity in the distribution of the 



Fig. 121. 



Fig. 122. 



Fig. 123. 






Fig. 121. Diagram of the Heart of the Mammal.— 7, Right auricle. 8, Right ven- 
tricle. 10, Pulmonic artery. 12, Pulmonic vein. 15, Left auricle. 16, Left ventricle. 

Fig. 122. Diagram of the Heart of the Reptile. — 1, Pericardium. 2, Single ven- 
tricle. 3, Left auricle. 4, Right auricle. The arrows show the direction of the blood. 

Fig. 123. Diagram of the Heart of the Fish.— 1, Pericardium. 2, The ventricle 
that receives the blood from the body. 3, The ventricle that sends blood to the gills. 



THE CIRCULATION. 



173 



Fig. 124. 



arteries of quadrupeds. In the long necks of grazing 
animals, there is found a large number of small arterial 
trunks, which are termed "Wonder Nets." Were these 
trunks few and large, as in man, the life of the animal 
would be endangered by the constant dependent position of 
the head. 

366. The blood of Birds has the highest temperature of 
the vertebrate ani- 
mals. It is richer 
in corpuscles than 
that of Mammals, 
and these corpus- 
cles are elliptical 
in form, instead of 
globular. The 
heart of birds is 
highly muscular, 
and of large size in 
proportion to the 
bulk of the body. 
The aorta, at its 
commencement, di- 
vides into three 
large branches, of 
which the first two 
convey the blood to 
the head and neck, 
wings, and muscles 
of the chest ; while 
the third, curving 
downward around 
the right bronchus, 
becomes the de- 
scending aorta. 
There are "Won- 
der Nets" in va- 
rious parts of the 

15* 




Fig. 124. Arteries of the Trunk of a Bird (the Grebe). 
— 1, The aorta. 2, The vena cava. 3, A cerebral artery. 
The small lines on each side represent the arteries and 
veins of the lungs. 



174 ANATOMY, PHYSIOLOGY AND HYGIENE. 



body, especially in the arteries supplying the brain, eyes 
and legs. 

Fig. 125. Fig. 126. 





Fig. 125. Circulation of a Reptile (a Lizard).— i, Heart. 2, Left auricle. 3, Right 
auricle. 4, Arches of the aorta. 5, Superior vena cava. 6, 10, Abdominal aorta. 7, Inferior 
vena cava. 8, Pulmonary artery. 9, Portal veins. 12, Lungs. 13, Stomach. 14, Intestines. 

Fig. 126. Blood- Vessels of a Fish.— 1, Auricle. 2, Ventricle. 3, Arterial bulb. 4, 
Bronchial artery (gill). 5, Bronchial vessels. 6, 10, Dorsal artery. 7, Venous sinus. 
8, Portal vein. 9, Vena cava. 11, Intestines. 12. Kidneys. 



THE CIRCULATION. 175 

367. In Reptiles, the blood is much cooler than in mammals 
and birds, and, having fewer globules, is lighter in color. 
The heart has only three cavities instead of four, viz., two 
auricles and one ventricle. The arterial blood coming from 
the lungs is received into the left auricle, and the venous 
blood from all parts of the body into the right auricle ; both 
are poured into the single ventricle, thus mixing the pure 
and impure blood, which will account for the sluggishness 
of these animals. A portion of this mixture returns by the 
aorta into the different organs it is intended to nourish, while 
another part proceeds to the lungs by vessels springing from 
the ventricle or the aorta. The arrangement of the blood- 
vessels of different classes of reptiles greatly varies, as some 
breathe by gills and others by lungs ; the frog in its early 
condition is furnished with the former, but in its later growth 
with the latter. 

368. In Fishes, the blood is cold, usually red, and the cor- 
puscles small and bi-concave. The heart has but two cavi- 
ties — one auricle and one ventricle, containing only impure 
blood ; this blood is sent to the gills, which answer the pur- 
pose of lungs, and, after being there exposed to the oxygen 
of air contained in the water and purified, it is distributed 
immediately to the different parts of the body, without the 
interposition of a heart. 



CHAPTER IX. 

ASSIMILATION. 

\ 37. Assimilation, General and Special. Formation of Different Por- 
tions of the Blood. Changes included under Secondary Assimilation. 
Secretion, or Special Assimilation. Excretion, characteristic of all Se- 
cretory and Excretory Glands. The Kidneys. 

369. In the human body, as elsewhere, the essential con- 
dition of physical life is death. While the vital force holds 
the mastery over the chemical forces, the more frequent the 
death-knell of the particles, the more abounding is the life. 
They perform their mission, yield up their vitality and pass 
away, while their places are supplied with new material. 
This new material is obtained from the food after its proper 
assimilation. As before stated, the processes by which food 
is converted into chyle, and then into blood, may be included 
under Primary Assimilation; while the changes which con- 
vert portions of the blood into solid tissue may be termed 
Secondary Assimilation ; both of these we will include under 
the head of General Assimilation, and the processes of secre- 
tion under Special Assimilation. 

370. The formation of chyle has already been fully noticed, 
and also its general relations to the blood. The white cor- 
puscles of the blood are supposed to be replenished from the 
corpuscles of the lymph and chyle, which enter the blood 
and are identical with its white corpuscles in size, form, struc- 
ture and general composition. Some suppose the red cor- 
puscles are developed from the white. 

The albuminous portion of the liquor sanguinis, or blood- 
plasma, is supplied from that of the lymph and chyle, and by 
the venous absorption of digested food ; but it may also con- 
tain more highly elaborated albuminoid materials derived 
from the corpuscles, whose elaborative office is undoubted. 
176 



ASSIMILATION. 177 

371. Secondary Assimilation, or Nutrition of the Organs 
and Tissues, consists of the following stages : 

First, A nutritive fluid, or plasma, exudes from the blood, 
through the coats of the capillaries, filling the finest inter- 
stices of the tissues between the capillary networks, and 
bathing all the elementary parts of those tissues. The nature 
of this plasma is the same in all parts of the system, and it 
is sometimes thought to be identical with the liquor sanguinis 
of, the blood, but this is doubtful ; it is more probable that 
the exuded plasma destined for the nutrition of the tissues is 
of a purer nutrient material. 

The second stage of the nutritive process consists in the 
exercise of a certain selective act by the elementary parts of 
tissues and organs, enabling them to appropriate to them- 
selves such portions of the nutritive fluid as are suitable, 
either with or without further change, to renew, molecule by 
molecule, their worn-out substance. " The nucleated cells of 
the epithelium and epidermis ; the corpuscles of the gray 
matter of the brain ; the tubular fibres of the white nervous 
tissue ; the complex fibres of the striated muscles ; the simple 
fibrous forms of the contractile non-striated muscles ; the 
fibres of the fibrous and areolar tissues ; and lastly, the con- 
solidated substance, with the remnants of cells imbedded in 
it, as in cartilage and bone — each derives from the exuded 
plasma of the blood, and assimilates its required constituents." 
This assimilating power of the tissue-elements is the persistent, 
primitive, nutritive force inherited from the germ-cell. It is 
probably possessed by every cell, however modified or remote 
in its descent from the parent cell. This power is greatest at 
the commencement of the life of any animal, and declines till 
the power to maintain the body is overcome by the forces 
which lead to its decay. 

Third, The result of the act of assimilation is to leave a 
residual fluid in the interspaces of the tissue-elements outside 
the capillary vessels. The nature of this fluid must differ in 
the different tissues, inasmuch as different tissues make dif- 
ferent appropriations. This fluid is not worthless, but only 

H* 



178 ANATOMY, PHYSIOLOGY AND HYGIENE. 

defective, and portions of it are probably taken up by the 
lymphatics, re-assimilated and returned to the blood through 
the absorbent system. 

Fourth, The final residue of the exuded plasma, that which 
is not taken up by the tissues nor lymphatics, is probably 
taken up by the venous capillaries. 

Fifth, With the final residuum are mingled the effete par- 
ticles of waste from the tissues, which also enter the venous 
blood, through the walls of the venous half of the capillaries 
and of the minute veins. These processes, though separately 
described, are, of course, in the living body, all going on at 
the same time, and continuously, and, in a healthy condition, 
with a perfect balance of action. 

372. Nutrition not only supplies the waste, but in new 
growth, new cell-elements, or germinal centres, are constantly 
reproduced and developed. This process occurs after the 
body has attained maturity, in the epidermis, nails, hair, the 
epithelial tissues, and probably the gray nervous substance, 
and perhaps in some of the other tissues. 

373. Special Assimilation, or Secretion, is the separa- 
tion from the blood of materials in a more or less fluid con- 
dition, through a gland or membrane. After assimilation, or 
secretion, the products are discharged from the ducts of the 
glands, or the surfaces of the membranes, and are used for 
certain purposes in the living economy. 

374. The secreting glands are the liver, the pancreas, the 
salivary and the lachrymal glands ; the true mucous glands 
of the nose, mouth, fauces, pharynx, oesophagus and duod- 
enum ; the simple tubular glands of the stomach and intes- 
tines ; the sebaceous and the mammary glands. The secreting 
membranes are the mucous, serous and synovial membranes. 
The serous and synovial fluids are little more than transuded 
materials of the blood-plasma, unaltered in chemical charac- 
ter, but modified in their relative proportions. By other 
secreting processes, substances are formed which do not exist 
in the blood, but resemble its constituents, being albuminoid 
in character ; as pepsin, pancreatin and salivin, etc. Others 



ASSIMILATION. 179 

differ from the blood in chemical constitution, and are very- 
complex in character, as certain acids of the bile, and the fat 
of the sebaceous secretions. Extreme examples of special 
secretive power, by which compounds not existing in the 
blood are formed from it, are afforded by the appearance of 
sulpho-cyanogen in the saliva, and of hydrochloric acid in 
the gastric juice ; so also soda is withdrawn from the normal 
soda salts of the blood, by the agency of the liver, to combine 
with the fatty acids of the bile. 

375. Excretion is effected by glands only, and the educts 
are eliminated from the blood and thrown out of the system. 
The excretoiy glands are the kidneys, the sweat glands of the 
skin ; to a certain extent, the liver, and, perhaps, the intes- 
tinal tubuli, especially of the large intestine, also the seba- 
ceous glands of the skin, and lastly, the lungs, which eliminate 
carbonic acid from the blood. 

In excretion, the substances eliminated from the blood 
pre-exist in that fluid as the result of decomposition, and 
are sometimes completely oxidized, and always to a greater 
extent than the secretions. The successive stages of oxida- 
tion remove substances more and more from an organiz- 
able character and necessitate their removal from the 
system. 

376. Ih all cases of Secretion and Excretion there is in- 
variably found, even in the ultimate ramifications of the 
gland-ducts, a basement membrane covered by a layer of 
epithelial cells. All glands are very vascular, and receive 
large quantities of blood. In many secretory processes the 
epithelial cells are ruptured, and their contents, and some- 
times the cells themselves, escape as an essential part of the 
secretion itself; as in the saliva, pancreatic fluid, gastric 
juice, the sebaceous and mucous secretions, and perhaps the 
bile; but the lachrymal and excretory processes simply 
withdraw their substances from the blood, and convey them 
from the body without themselves undergoing dissolution or 
decay. 

377. The numerous glands and membranes have been 



180 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



noticed in other relations, with the exception of the kidneys 
and the glands of the skin. 

378. The Kidneys lie one on each side of the spinal 
column, in a line with the lowest dorsal and the two or three 



Fig. 12S. 



Fig. 127. 




Fig. 127 (Leidy). Longitudinal Section of a Kidney.— 1, Cortical substance. 2, 
Renal pyramid. 3, Renal papillae. 4, Pelvis. 5, Ureter. 6, Renal artery. 7, Renal 
vein. 8, Branches of the latter vessels in the sinus of the kidney. 

Fig. 128 (Leidy). Diagram of the Structure of the Kidneys. — 1, Two uriniferous 
tubules of the cortical substance lined with a pavement epithelium. 2, Dilatation of a 
tubule at its extremity. 3, Branch of the renal artery ending in vessels which enter 
the dilatations as seen at 4. 5. 6, Knot of blood-vessels freed from its investment. 
7, Veins emerging from the vascular knots. 8, Plexus formed by the latter veins 
among the uriniferous tubules, from which plexus originate the branches of the renal 
vein. 

upper lumbar vertebrae; the right kidney is a little lower 
than the left. Their shape is that of a bean, and their color 
a brownish red. They are made up of two very different 
substances, one covering the whole organ, called the Cortical 



ASSIMILATION. 181 

substance : the other is called the Medullary substance, and 
consists of a series of pyramids, with their bases toward the 
surface of the organ, and their summits, or renal papillae, 
toward the fissure. The substance of the kidney is mainly 
composed of secretory tubes, named Uri 'niferous tubules, and 
blood-vessels, with little connective tissue. These tubules are 
conyoluted in the cortical substance, and straight in the 
medullary, where the terminal orifices are seen by hundreds 
at the summit of each renal papilla. The tubes are lined 
with an epithelium which secretes the urine. This secretion 
is conveyed to the bladder by a cylindrical tube about 
eighteen inches in length, called the Ureter. 

Observation. — The retention of the secretion of the kidneys 
should never be allowed by the young or the old, the healthy 
or the diseased, as suppression of the secretion of these glands 
immediately affects the whole system, especially the nervous 
centres. Both the quantity and color of this secretion indi- 
cate the condition or health of the body. 

379. The glands of the skin will be described in Chap- 
ter XII. 

16 



182 ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 129. 




Fig. 129. A Front View of the Organs of the Chest and Abdomen. — 1, 1, 1, 1, The 
muscles of the chest. 2, 2, 2, 2, The ribs. 3, 3, 3, The upper, middle and lower lobes of 
the right lung. 4, 4, The lobes of the left lung. 5, The right ventricle of the heart. 6, 
The left ventricle. 7, The right auricle of the heart. 8, The left auricle. 9. The pul- 
monary artery. 10, The aorta. 11, The vena cava descendens. 12, The trachea. 13, 
The oesophagus. 14. 14, 14, 14, The pleura. 15, 15, 15, The diaphragm. 16, 16, The right 
and left lobes of the liver. 17, The gall-cyst. 18, The stomach. 26, The spleen. 19,19, 
The duodenum. 20, The ascending colon. 21, The transverse colon. 25, The descend- 
ing colon. 22, 22, 22, 22, The small intestine. 23, 23, The abdominal walls turned down. 
24, The thoracic duct, opening into the left subclavian vein (27). 



CHAPTER X. 

THE RESPIRATORY AND VOCAL ORGANS. 

$ 38. Anatomy of the Kespiratory and Vocal Organs. — The 
'Organs of the Voice and of Respiration — The Larynx — Trachea — 
Bronchi — Lungs. 

380. The Respiratory and Vocal Organs consist of 
the Larynx, the Trachea, the Bronchi and the Lungs, the 
whole being acted upon by a complicated series of muscles. 

381. The Larynx, the organ of the voice, is a short, 
quadrangular, cartilaginous cavity, extending from the root 
of the tongue and the hyoid bone, to the trachea, with which 
it becomes continuous below. It is separated from the spinal 
column by the pharynx, into which it opens above by a 
triangular and oblique aperture. 

The Larynx is composed of five principal parts — the Thy- 
roid, the Cri'coid, the two Arytenoid cartilages, and the 
Epiglottis. The Thyroid* is the largest cartilage. It con- 
sists of two lateral, quadrangular, wing-like plates, which 
meet in front and form the prominence called pomum Adami 
(Adam's apple). This cartilage is connected with the hyoid 
bone above, and with the cricoid cartilage below. 

The Cricoid^ cartilage is about one-fourth of an inch wide 
in front, and one inch behind. This cartilage connects above 
with the thyroid cartilage by an articulation permitting the 
latter to move downward and forward, and also in the re- 
verse direction; below, it communicates with the first ring 
of the trachea. 

The Arytenoid^ cartilages are two in number, small, tri- 



* Gr., thureos, a shield. f Gr., krikos, a ring. 

X Gr., arutaina, a pitcher. 

183 



184 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



angular and curved. They are placed upon the summit and 
back part of the cricoid cartilage, forming articulations. 

The Epiglottis is oval-shaped, having its convex surface 
toward the mouth. It stands in a vertical position above 
the aperture of the larynx, which is closed by it in the act 
of swallowing. 



Fig. 130. 



Fig. 131. 





Fig. 130. A Side View of the Cartilages of the Larynx. — *, The front side of the 
thyroid cartilage. 1, The os hyoides (bone at the base of the tongue). 2, The ligament 
that connects the hyoid bone and thyroid cartilage. 3, 4, 5, The thyroid cartilage. 6, 
The cricoid cartilage. 7, The trachea. 

Fig. 131. A Back View of the Cartilages and Ligaments of the Larynx.— 1, The 
posterior face of the epiglottis. 3, 3, The os hyoides. 4, 4, The lateral ligaments which 
connect the os hyoides and thyroid cartilage. 5, 5, The posterior face of the thyroid 
cartilage. 6, 6, The arytenoid cartilages. 7, The cricoid cartilage. 8, 8, The junction 
of the cricoid and the arytenoid cartilages. 12, The first ring of the trachea. 

382. The Trachea is a vertical tube about an inch in 
diameter and four inches in length. It is continuous with 
the larynx and extends to the third dorsal vertebra, where it 
divides into two branches, called Bronchi. The trachea is 
separated from the spinal column by the oesophagus. 

383. The Bronchi* carry air to their respective lungs, 
and again divide, sending a branch to each lobe. These 



Gr., brogchia, the windpipe or throat. 



THE KESPIRATORY AND VOCAL ORGANS. 



185 



divisions, called bronchise, are repeated, until each ultimate 
ramification terminates in a dilatation, called an air-cell. 

384. The Lungs, consisting of two divisions, are situated 
in the cavity of the chest, enclosing between them the heart 
and the great blood-vessels. They accurately fill the cavity, 
adapting themselves to the varying size attending respira- 
tion. They have the form of a double, but very irregular 
cone, with the apices above, and the basal ends below. The 
outer surfaces are convex, fitting the form of the chest ; the 
inner surfaces are concave, conforming to the shape of the 
heart ; the basal portion is also concave, owing to the upward 
pressure of the diaphragm. They are everywhere unattached, 
excepting at the root, where they are firmly secured by the 
pulmonary ligaments, the pulmonary artery, the pulmonary 
veins and nerves, and the bronchial tubes. The lungs are 
closely invested with a serous membrane, named pleura. The 
right lung is shorter than the left, but wider, and of somewhat 
greater bulk. It is divided into three lobes ; the middle lobe 
being the smallest, and the lowest one the longest. The left 
lung has two lobes, of which the lower is the larger. 



Fig. 133. 



Fig. 132. 




Fig. 132. The Lungs.— 3, 3, 3, The lobes of the right lung. 4, 4, The lobes of the left 
lung. 5, 6, 7, The heart. 9, 10, 11, The large blood-vessels. 12, The trachea, 15, 15, 15, 
The diaphragm. 

Fig. 133. The Bronchia— 1, Outline of right lung. 2, Outline of left lung. 3, 4, 
Larynx and trachea. 5, 6, 7, 8, Bronchial tubes. 9, 9, Air-cells. 
16* 



186 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



$ 39. Histology of the Kespiratory and Vocal Organs. — 

Minute Structure of the Larynx. — The Trachea — The Bronchi — The 
Lungs and Pleura. 

385. With the exception of the epiglottis, the so-called 
cartilages of the Larynx are true cartilage, and in advanced 
life are strongly disposed to ossify. They are invested with 
a periehon' drium* The articulations of the cricoid cartilage 
are lined with synovial membrane and covered with capsular 
ligaments. The epiglottis is of a soft, elastic nature, fibro- 
cartilaginous in structure, and invested with mucous mem- 
brane. 

Fig. 135. 

Fig. 134. 





Fig. 134. A View of the Larynx, showing the Vocal Ligaments. — 1, The anterior 
edge of the larynx. 4, The posterior face of the thyroid cartilage. 5, 5, The arytenoid 
cartilages. 6, 6, The vocal ligaments. 7, Their origin within the angle of the thyroid 
cartilage. 8, Their termination at the base of the arytenoid cartilages. 8, 10, The glottis. 

Fig. 135. An Ideal Section of the Larynx. — 1, The trachea. 2, 2, The lower vocal 
cords. 3, 3, The upper vocal cords. 4. 4, Rima glottidis, or glottis- 5, 5, Cavities be- 
tween upper and lower vocal cords. 

386. In the cavity of the larynx, the mucous membrane is 
reflected at each side, outward and upward, forming a pair 
of pouches, called the ventricles of the larynx. Just below 
these ventricles, are the true vocal cords, extending from a 
small process on the fore part of each Arytenoid cartilage to 
the recessed part of the Thyroid cartilage. They are com- 



* Gr., peri, around, and chondros, a cartilage. 



THE RESPIRATORY AND VOCAL ORGANS. 187 

posed of yellow elastic tissue, covered by mucous membrane, 
and form two ridges, having very fine, smooth edges turned 
toward each other, and placed accurately on the same level. 

387. The Trachea is made up of cartilage, fibrous tissue, 
muscle and mucous membrane. The cartilaginous part con- 
sists of flattened rings, or rather segments of circles, as they 
are wanting in that part of the tube next to the spine. The 
last ring is so modified as to accommodate it to the two first 
rings of the bronchi. The fibrous part is of yellow elastic 
tissue. It commences at the cricoid cartilage, and not only 
covers the rings in front, but forms for each a distinct sheath, 
thicker in front, and gradually losing itself with the termina- 
tion of the rings. The posterior third of the trachea has a 
basis of strong, elastic fibrous tissue, arranged in longitudinal 
bands. The muscular portion has a simple layer of fibres 
running transversely, being attached to the ends of the car- 
tilaginous rings and to the connecting tissue. The trachea is 
lined with mucous membrane. 

388. The Bronchi are constructed like the trachea, ex- 
cepting in the ultimate bronchial ramifications, where the car- 
tilages are composed of several pieces distributed around the 
tube, and the muscular fibres form a continuous layer. The 
cartilaginous element finally disappears, when the tubes con- 
sist only of fibro-elastic membrane with muscular fibres and 
a lining mucous membrane. 

389. The Lungs are made up of numerous small, poly- 
hedral, primary lobules, or clusters of air-cells, which unite 
into larger secondary lobules. The latter give rise to the 
polyhedral markings seen upon the external surface of the 
lungs. The lobules seem to have no communication with 
each other, each primary lobule being in itself a miniature 
lung, performing independent functions. It has been cal- 
culated that no less than eighteen thousand of these air-cells 
group around each terminal tube, giving a sum-total of not 
less than six hundred millions. 

The air-cells are connected together by fibro-elastic tissue, 
which renders them highly elastic. The cells are surrounded 



188 



ANATOMY., PHYSIOLOGY AND HYGIENE. 



Fig. 136. 



by fine networks of capillary vessels, the terminations of the 
branches of the pulmonary artery which accompany the 

branches of the bronchi. The tra- 
chea, bronchial tubes and air-cells 
are lined with a mucous membrane 
having a ciliated epithelium. 

390. The Pleura is a serous 
membrane which lines the thorax 
and then is reflected from the root 
of each lung over its surface. A 
fold of this membrane extends from 
the root downward to the diaphragm, 
and is called the pulmonary liga- 
ment. The pleural cavity is lubri- 
cated by the serous secretion, thus 
preventing friction during the re- 
spiratory movements (43). By the 
approximation of the two pleurse in 
the median line, they form the mediastinum, or partition of 
the thorax, which contains the heart enclosed within its 
pericardium. 




Fig. 136 (Leuly). Diagram of 
Two Primary Lobules of the 
Lungs, magnified. — 1, Bronchial 
tube. 2, A pair of primary lob- 
ules connected by fibro-elastic 
tissue. 3, Inter-cellular air-pas- 
sages. 4, Air-cells. 5, Branches 
of the pulmonary artery and 
vein. 



\ 40, Chemistry of the Kespiratory and Vocal Organs. 

391. Respiration consists of two conjoint processes : that 
of supplying to the body the requisite amount of vitalizing 
oxygen, by inspiration ; and that of removing from the body 
the deleterious carbonic acid, by expiration. The source of 
the oxygen is the air ; the sources of carbonic acid are the 
blood and the tissues. 

392. Some carbonic acid is generated in the blood, both 
from the respiratory or heat-giving elements of food, which 
chiefly enter the blood and are there oxidized, and from the 
changes of growth and decay to which the corpuscles of 
the blood are themselves subject. It is also probable that 
some intermediate or partly oxidized products of the de- 
composition of solid tissues undergo further oxidation in the 
blood. 



THE KESPIRATOKY AND VOCAL ORGANS. 189 

393. We find the main source of carbonic acid, however, 
in the tissues. It appears both as a product of their natural 
decay, and of muscular and nervous activity. The sum of 
all the chemical changes of the body is oxidation, and the 
chief product of this oxidation is carbonic acid. 

394. The proportions of oxygen and carbonic acid in 
venous and arterial blood are — 

Oxygen. Carbonic Acid. 

100 vols, venous blood ... , 5 vols. 25 vols. 

100 vols, arterial blood 10 vols. 20 vols. 

It has also been found that the proportions of oxygen and 
carbonic acid in venous blood returning from muscles at rest 
are — oxygen, 7.5 vols. ; carbonic acid, 31 : from muscles in 
action: oxygen, 1.265 vols.; carbonic acid, 34.4. 

395. The exchange of oxygen and carbonic acid in the 
capillaries is effected partly by physical and partly by 
chemical processes. The physical process is in accordance 
with the law of the " diffusion of gases." Two gases of dif- 
ferent densities, and having no chemical affinity for each 
other, will intermix when brought into contact, and also 
when separated by a porous septum, provided they have no 
chemical affinity for that septum. These are the exact con- 
ditions in the capillaries ; the oxygen and carbonic acid are 
the two gases, the capillary walls the porous septum. In 
addition to this physical process, there is a chemical process ; 
the venous blood has a strong affinity for oxygen, hence 
readily unites with it in the pulmonic capillaries. When the 
arterial blood reaches the systemic capillaries, it yields its 
oxygen to the elements of the decomposing tissues which sur- 
round them. The carbon and hydrogen in their nascent 
state, or at the moment of liberation, seize the oxygen with 
great avidity, and give in exchange carbonic acid and water. 

396. The air of expiration differs from that of inspiration, 
not only in its increase of carbonic acid, but in that of moisture 
and of temperature. As a rule, the expired air is saturated 
with moisture. The drier the external air, the greater the 
pulmonary exhalation, for in breathing air already saturated, 



190 ANATOMY, PHYSIOLOGY AND HYGIENE. 

only so much more can be added as the higher temperature 
of the body will enable it to dissolve. The pulmonary ex- 
halation has, besides water and carbonic acid, traces of 
ammonia, chlorides, urates, and even some albuminous sub- 
stances ; it readily undergoes decomposition. 

397. The heat of the body is the result of the various 
chemical actions. The temperature of the tissues generally 
ranges from 98° to 100° ; that of blood, from 100° to 102°. 
The blood varies in temperature in different parts, being 
warmest in the hepatic veins. 

I 41. Physiology of the Eespiratory and Vocal, Organs. — 

Objects of Respiration. Two Modes of Respiration. Renovation of the 
Air in the Lungs. Amount of A ir concerned in each Respiration. 
Conditions affecting the Number of Respirations. Modifications of Re- 
spiratory Movements. Double Function of the Larynx. Resemblance 
between the Action of the Vocal Cords and Reed Instruments. Con- 
ditions affecting the Tone and Strength of the Voice. 

398. The Function of Respiration has for its imme- 
diate object, the purification of the blood, and for its ultimate 
uses, the production of heat, motion and nervous energy. The 
blood which becomes impure in the systemic capillaries, is 
carried to the pulmonary capillaries, which everywhere sur- 
round the air-cells. Through the thin walls, the poisonous 
carbonic acid passes from the capillaries into the air-cells, 
and is expelled from the body ; at the same time, the oxygen 
of the external air passes from the air-cells into the capil- 
laries, and the blood is changed from a dark maroon, to a 
bright red color. 

The chemical changes in every part of the body caused by 
the union of this oxygen with carbon, hydrogen and other 
elements of the blood and tissues, maintain the temperature 
of the body, and are the source of its nervous power and 
electricity. 

399. Respiration consists of two acts — taking air into the 
lungs, or inspiration, and expelling air from the lungs, or 
expiration. An act of inspiration is effected by the enlarge- 



THE RESPIRATORY AND VOCAL ORGANS. 



191 



ment of the chest, which is done by elevating the ribs and 
sternum, and depressing the convex surface of the diaphragm. 
To elevate the ribs, two sets of muscles are used ; those which 
are attached to the upper rib and sternum, contract and ele- 
vate the anterior extremities of the ribs; this enlarges the 
cavity between the spinal column and the sternum. The 
central portion of the ribs are raised by the intercostal 
muscles. The second rib is elevated by the contraction of 
the muscles between it and the first ; the third rib is raised, 
by the combined action of the muscles between the first and 
second, and between the second and third. 



Fig. 137. 




Fig. 137. A Front View of the Chest and Abdomen in Respiration.— 1, 1, The 
position of the walls of the chest in inspiration. 2, 2, 2, The position of the diaphragm 
in inspiration. 3, 3, The position of the walls of the chest in expiration. 4, 4, 4, The 
position of the diaphragm in expiration. 5, 5, The position of the walls of the abdomen 
in inspiration. 6, 6, The position of the abdominal walls in expiration. 

The motion of each succeeding rib is increased in the same 
way, so that the movement of the twelfth rib is very free, as it is 
elevated by the contraction of eleven sets of intercostal muscles. 
Simultaneously with the elevation of the ribs, the central por- 



192 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



tion of the diaphragm is depressed by the contraction of its 
muscular margin and the relaxation of the muscular walls of 
the abdomen. By these combined movements the chest is en- 
larged in every direction. This enlargement of the thorax 
tends to produce a vacuum between the thoracic walls and 
the lungs, hence, the pressure of the external air fills the air- 
cells, forcing the elastic lungs to expand and fill the cavity ; 
as when an elastic membrane is fitted over an open-mouthed 
vessel connected with an air-pump ; exhaust any portion of 
the air within, and the pressure of the external air will cause 
the membrane to assume a convex form, the convexity being 
within the vessel. 

Fig. 138. 




Fig. 138. A Side View of the Chest and Abdomen in Respiration. — 1, The cavity 
of the chest. 2, The cavity of the abdomen. 3, The line of direction for the diaphragm 
when relaxed in expiration. 4, The line of direction for the diaphragm when contracted 
in inspiration. 5, 6, The position of the front walls of the chest and abdomen in inspira- 
tion. 7, 8, The position of the front walls of the abdomen and chest in expiration. 



The elastic walls of the air-cells yield in every direction, 
so also do the surrounding areolar tissue and the pleura ; 



THE RESPIRATORY AND VOCAL ORGANS. 193 

the air-tubes yield both in a circular and a longitudinal 
direction. 

400. In expiration, the movements are of a more passive 
character, depending mainly on the relaxation of the inspira- 
tory muscles and the elastic resilience of the tissues concerned. 
When the muscles relax, the sternum and ribs descend ; the 
diaphragm vaults upward ; the elastic walls of the air-cells 
diminish their size ; the longitudinal and circular fibres of 
the, bronchi and bronchia? shorten and narrow their tubes; 
and the entire elastic lungs rebound like an extended spring 
let loose, while the interlobular and sub-pleural tissues aid 
powerfully in compressing them on all sides. 

Ordinary expiration is undoubtedly aided by the action 
of proper expiratory muscles, especially the internal inter- 
eostals and the infracostals, small muscular bundles having 
the same direction as the former, but reaching over two or 
three spaces, instead of a single space between two ribs ; also 
by a portion of a thin layer within the sternum and the car- 
tilages of the true ribs. 

The auxiliary expiratory muscles are the serratus magnus, 
the serrated muscles passing from certain dorsal and lumbar 
vertebrae upward to the last four ribs, and those which ascend 
from the pelvis and lumbar vertebrae to the lower ribs, cer- 
tain portions of the long muscles of the back, and, lastly, the 
abdominal muscles. In difficult respiration almost every 
muscle in the body is made in some way subservient to the 
distension of the chest. 

401. When respiration is performed chiefly by the dia- 
phragm, it is called abdominal respiration; when chiefly by 
the action of the ribs, pectoral respiration. The former is 
the characteristic mode in men and children ; the latter, in 
women. 

402. The ordinary respiratory movements alone would not 
renovate the air in the smaller air-tubes and air-cells. Ad- 
ditional aid is rendered in two ways : 1st, By the diffusion of 
gases, causing the carbonic acid and the oxygen to mix 
equally in all parts of the lungs; and 2d, By the epithelial 

17 T 



Fig. 139. 




194 ANATOMY, PHYSIOLOGY AND HYGIENE. 

air-current. In the lining mucous membrane of the trachea 
and the bronchial tubes, the cilia of the epithelium are always 
directed from below upward, and, like all ciliary motion, it 
has the effect of producing a current in the fluids of the mu- 
cous membrane (41). 
Now, the air in the 
tubes must move, to a 
certain extent, with 
this current, hence, a 
double stream of air 
is established in each 
bronchial tube ; one 

Fia. 139. Diaobam or a Small Bronchial Tube, CUY ™ Ut !»*"« fr0m 
showing outward and inward current, produced by within OUtward, along 

ciliarymotion - the walls of the tube, 

the other passing from without inward, along the central 
part. Thus a kind of aerial circulation is maintained, which, 
together with the mutual diffusion of the gases and the ordi- 
nary respiratory movements, ensures a complete renovation 
of the air in all portions of the pulmonary cavity. 

403. The amount of air taken in and given out in a re- 
spiratory movement must vary with different individuals 
and different conditions of the system. The volume of air 
ordinarily received by the lungs in a single inspiration is 
about one pint; the volume expelled, a little less than a pint. 
In the mutual action that takes place between the air and the 
blood, every twenty-four hours, the air loses about thirty- 
seven ounces of oxygen, and the body fourteen ounces of 
carbon. 

404. Respiration is more frequent in women and children 
than in men. Persons of small stature breathe more fre- 
quently but less deeply than taller people. In health, the 
smallest number of respirations in a minute, by an adult, is 
not less than fourteen, and they rarely exceed twenty-five; 
eighteen may be considered the average number. The num- 
ber of respirations is increased by exercise, food, stimulants 
and moderate cold ; while it is diminished by inactivity, 



THE RESPIRATORY AND VOCAL ORGANS. 195 

moderate heat, starvation and general weakening influences, 
especially mental depression. 

405. The actions of sighing, yawning, sobbing, laughing, 
coughing and sneezing are simple modifications of the ordi- 
nary movements of respiration, excited either by mental 
emotions, or by a stimulus arising in the respiratory organs 
themselves. Sighing and yawning often occur as simple re- 
sults of deficient aeration ; sometimes the former results from 
depression of the feelings ; the latter from mere imitation. 
Laughter and weeping seem to be always either expressions 
of the emotions, or simple results of sensations. Coughing 
and sneezing are occasioned by irritation in the air-passages, 
and the sudden expiratory movement has a tendency to re- 
move all intruding substances. 

406. The Larynx performs a double function, one part 
being concerned with respiration ; the other with the voice. 

In inspiration, the vocal cords separate, allowing the air 
to pass in freely ; in expiration they relax. The former 
movement is active; the latter, passive. Both co-operate 
with the other respiratory movements. The extreme sensi- 
bility of the vocal cords and the posterior part of the epi- 
glottis, causes them to throw off any foreign substances hap- 
pening to come in contact with them, by a sudden, expulsive 
cough. 

The larynx, however, is the special organ of the voice; 
sounds being produced by the vibratory action of the vocal 
cords. During ordinary, tranquil breathing, the cords are 
widely separated, the glottis being of triangular shape, but 
when a vocal sound is to be produced, the arytenoid cartilages 
are said to become erect, and almost to touch each other; the 
cords are made suddenly tense, closing the posterior portion 
of the glottis, while the anterior two-thirds opens a very fine 
fissure ; and the air, driven by an unusually forcible expira- 
tion through the narrow opening in passing between the 
vibrating vocal cords, is itself thrown into vibrations which 
produce the sound required. 

407. The vibrations of the vocal cords take place according 



196 ANATOMY, PHYSIOLOGY AND HYGIENE. 

to the laws which regulate the action of the stretched mem- 
branous tongues, or reeds, in reed instruments. If one ex- 
tremity of a short tube be covered by two portions of elastic 
membrane, leaving a small chink between them, a form of 
double membranous tongue is obtained, which resembles the 
vocal cords in man. The narrower the chink, the more 
easily are sounds produced. The size, however, in no way 
affects the pitch, which is somewhat determined by the 
length, tension and thickness of the tongues, but chiefly by 
the tension. 

408. The tones of different individuals are doubtless modi- 
fied by the shape and size of the vocal apparatus. Thus, a 
large larynx usually gives a deep-toned voice ; a smaller one 
gives a comparatively high pitch. The difference in the tone 
of the male and female voice is due largely to the great dif- 
ference in the walls of the larynx. In the female, the cavity 
is smaller, the angle in front less acute, and the cartilage 
softer. 

Vocal sounds are further modified by the elevation and 
depression of the larynx, for when the voice is raised from a 
low to a high pitch, the whole larynx is elevated toward the 
base of the skull, drawing with it the trachea; the vocal 
tube is thus slightly lengthened ; the diameter of the trachea 
lessened and variations are produced in the tension of its 
w T alls, enabling it to accommodate itself to the different vocal 
tones. 

The general strength of the voice depends upon the capacity 
of the chest ; the development of the muscles used in vocaliza- 
tion ; the extent to which the vocal cords can vibrate ; and 
the power of communicating resonance possessed by the air- 
passages and neighboring cavities. 



THE RESPIRATORY AND VOCAL ORGANS. 197 



I 42. Hygiene of the Respiratory and Vocae Organs. — Im- 
portance of Proper Respiration. Effect of Carbonic Acid Gas upon 
Respiration and Combustion. Sources of this Gas. Location of Dwell- 
ings. Danger of Impure Air within the House. Importance of Ventila- 
tion in Public Buildings — In Sleeping Rooms — In Sick Rooms. Means 
of Securing Warm and Pure Air in Winter. Importance of Moisture 
in the Air. Effect of Compressing the Respiratory Organs. Means of 
Enlarging the Chest. Influence of the Nervous System upon Respira- 
tion. 

409. In the circulating system, we have seen the minutest 
care manifested in supplying each organ, tissue and cell with 
blood ; if the blood be pure, this is the best conceivable 
arrangement for securing health and vitality ; if impure, the 
means is equally J effective for poisoning every part of the 
system. 

410. That pure blood can be obtained only by a healthy 
action of the respiratory organs, and this action only by a 
constant and sufficient supply of pure air, is evident from 
what has already been said. Limit this supply, and a double 
evil ensues; the stimulus furnished to the tissues, especially 
the nervous and muscular, is withdrawn, and the carbonic 
acid is retained in the blood ; hence, the brain works slug- 
gishly ; the muscles become inactive ; the heart acts im- 
perfectly ; the secretions are deteriorated ; the food is not 
properly assimilated ; and the whole body becomes weak. 

411. Pure air is composed of oxygen and nitrogen in about 
the proportion of 21 to 79. The air is most frequently ren- 
dered unfit for vital purposes by the presence of carbonic 
acid gas, and volatile particles of corrupted animal matter. 
Carbonic acid gas will not support combustion, as may be 
seen by introducing into it a burning taper, which is as 
readily extinguished as if dipped in water; neither will it 
support life ; if a small animal be placed in a jar of the gas, 
life soon becomes extinct. 

412. The sources of this deleterious gas are mainly — de- 
caying animal and vegetable matter ; combustion ; and the 
respiration of animals. 

17* 



198 ANATOMY, PHYSIOLOGY AND HYGIENE. 

Plants in their healthy state take up carbonic acid gas, 
and give out oxygen, thus maintaining, under ordinary cir- 
cumstances, a pure and respirable atmosphere. 

In wells, mines and caves, where the circulation is ob- 
structed, this gas often accumulates in quantities sufficient to 
cause death to those who enter. Hence, before entering 
them, the air should be tested by a lighted taper. If it will 
not burn, respiration cannot be maintained. 

413. The location of dwelling-houses should be chosen with 
reference to free circulation of air, and the avoidance of marshes, 
stagnant pools, slaughter -houses, and other sources of vegetable 
and animal decay. Careful attention should also be given 
to the drainage of a house, and to the cellar. These under- 
ground store-rooms should always be well ventilated, and all 
vegetables removed from them in early spring. A little 
neglect in these and like respects has not unfrequently pros- 
trated a whole family with typhoid disease. 

414. The chief danger, however, is within the house proper, 
and from the breaths of its inmates. Unless ventilation re- 
ceives proper attention, the carbonic acid gas from the lungs, 
and the effete particles of animal matter thrown off from the 
system, will soon render the air poisonous. 

415. School-rooms, churches, concert-halls and all rooms de- 
signed for public purposes should be amply ventilated. The 
child at school becomes listless and uninterested : why? Be- 
cause he is stupefied by foul air. When a pupil continues to 
breathe such air, month after month, his brain is injured, 
and often consumption or other fatal disease destroys his 
young life, and then we wonder at the " mysterious provi- 
dence " that takes from us the gifted and beautiful. 

The good man at church feels that he ought to be interested 
in the services, and yet, powerless to fix his attention, he sits 
nodding: why? Because he is stupefied by foul air. The air 
breathed over and over again last Sabbath, and shut in during 
the week, is all the poor man can obtain. How can acceptable 
worship be offered by those who are, at the very moment, vio- 
lating the plainest laws of the Being worshiped ? 



THE RESPIRATORY AND VOCAL ORGANS. 199 

416. The lamps of the concert-hall burn dimly long before 
the closing hour : why ? Because they are bedimmed by the 
foul air ; and just in proportion to the decrease of light is 
the increase of dullness in the audience. Let in the pure air, 
and how soon will the light perceptibly brighten, and the 
audience become animated. The air of a well-filled school- 
room, church or hall, will be rendered unfit for respiration 
in a Jew minutes. 

417. The influence of habit, in accustoming us to foul air, 
is strikingly expressed by Birnan, in the " Art of Warming 
and Ventilating Rooms " : " Not the least remarkable example 
of the power of habit is its reconciling us to practices which, 
but for its influence, would be considered noxious and dis- 
gusting. We instinctively shun approach to the dirty, the 
squalid and the diseased, and use no garment that may have 
been worn by another. We open sewers for matters that 
offend the sight or the smell and contaminate the air. We 
carefully remove impurities from what we eat and drink, 
filter turbid water, and fastidiously avoid drinking from a 
cup that may have been pressed to the lips of a friend. On 
the other hand, we resort to places of assembly, and draw 
into our mouths air loaded with effluvia from the lungs, skin 
and clothing of every individual in the promiscuous crowd — 
exhalations offensive, to a certain extent, from the most 
healthy individuals ; but when arising from a living mass of 
skin and lungs in all stages of evaporation, disease and 
putridity, prevented by the walls and ceiling from escaping, 
they are, when thus concentrated, in the highest degree dele- 
terious and loathsome." 

418. The sleeping room should be thoroughly ventilated. 
Proper ventilation would often prevent morning headaches, 
want of appetite and general languor, so common among the 
feeble. The impure air of sleeping rooms probably causes 
more deaths than intemperance. Those who live in open 
houses little superior to the sheds that shelter the farmer's 
flocks, are usually the most healthy and robust. Headaches, 
liver complaints, coughs, and a multitude of nervous affec- 



200 ANATOMY, PHYSIOLOGY AND HYGIENE. 

tions, are almost unknown to them ; not so with those who 
spend their days and nights in rooms with double or calked 
windows, breathing over and over again the confined air ; 
disease and suffering are their constant companions. 

Observation. — 1st, By many, a sleeping apartment twelve 
feet square and seven feet high, is considered spacious for 
tw r o persons, and "good accommodation" for four. This 
room contains one thousand and eight cubic feet of air; 
allowing ten cubic feet to each person per minute, two occu- 
pants would vitiate the air in fifty minutes, and four in 
twenty-five minutes. 

2d, Among children, convulsions, or fits, often occur when 
they are sleeping, and not unfrequently in consequence of im- 
pure air. In such cases, by carrying the sufferer into the 
open air, relief is afforded. Children should not sleep in low 
beds, while adult persons occupy a higher bed in the same 
un ventilated room, as carbonic acid is most abundant near 
the floor, nor is it advisable that the young sleep with the 
sick or aged. 

419. The ventilation of the sick room should receive special 
attention. It is no unusual practice, when the patient is suf- 
fering from acute disease, for the attendants to prevent the 
ingress of pure air, simply from the apprehension that the 
sick person will take cold ; and caution is indeed necessary ; 
the patient should not feel the current. No room is suitable 
for sickness that is not so arranged that pure air may be 
constantly admitted without inconvenience or injury to the 
patient ; and here we would say that cool air should not be 
mistaken for pure air. A very little sound judgment in this 
matter would doubtless save much suffering, and lengthen 
life in a multitude of cases. 

The custom of having several persons sit in the sick room 
vitiates the air and delays the recovery of the patient. 

420. The great means of ventilation, in summer, are open 
windows and doors. Motion is at that season the great de- 
sideratum. On a hot summer's day we go into a cool room 
that has been shut up, and at first it is grateful; but in a 






THE RESPIRATORY AND VOCAL ORGANS. 201 

short time, the cool, stagnant air becomes oppressive, and we 
select the open window with its circulation of air, even if it is 
a little warmer. Windows should be made to lower from 
the top. 

421. In winter, ventilation may be obtained by properly con- 
structed flues. As cold weather approaches, we must close 
the windows, excepting when in bed ; but good flues secure a 
good circulation of air. Leeds, in his " Lectures on Ventila- 
tion/' in speaking of the value of an open fireplace for 
ventilation, says, " Thousands of lives are thus saved, and 
many more would be, if all fireplaces were kept open. If 
you are so fortunate as to have a fireplace in your room, 
paint it when not in use ; put a bouquet of fresh flowers in it 
every morning, if you please, or do anything to make it 
attractive, but never close it; better use the fire-boards for 
kindling-wood. It would be scarcely less absurd to take a 
piece of elegantly- tinted court-plaster and stop up the nose, 
trusting to the accidental opening and shutting of the mouth 
for fresh air, because you thought it spoiled the looks of your 
face to have two such great, ugly holes in it, than to stop 
your fireplace with elegantly-tinted paper because it looks 

better." 

422. For heating a small room, where the occupants may 
change position at pleasure, an open fire is the healthiest 
known means, for the air cannot become stagnant, as the fire 
is continually drawing a considerable amount from the room 
to support combustion, the place of which is supplied by 
other air. Just here comes in the greatest inconvenience of 
the open fire ; if the cold air comes in at the cracks of a door 
or window on the opposite side of the room, it will flow across 
to the fire, chilling the feet and backs of those sitting in its 
track. 

423. A stove is a very economical mode of heating ordi- 
nary sitting rooms, offices, etc. ; but there should be an air- 
chamber, or box, on or near the top of the stove, and com- 
municating with this should be a pipe for introducing fresh 
air from the external atmosphere. If this supply of fresh air 

I* 



202 ANATOMY, PHYSIOLOGY AND HYGIENE. 

is abundant, with a constant evaporation of moisture, and an 
opening into a heated flue near the ceiling, to be opened 
when the room is overheated or the lights are burning in the 
evening, and kept closed at other times, with another open- 
ing into a heated flue on a level with the floor, which should 
be always open to carry off the cold, heavy, foul air from the 
floor ; if a stove be thus arranged, for many small, isolated 
rooms, it is one of the most economical, comfortable and 
wholesome means of heating at our command. 

424. For the general warming of a house, heating the air 
by steam is one of the most healthy arrangements, and a 
very good mode is thus given by Leeds : " Where a steam 
furnace is used, two-thirds of the heating surface should be 
below the floor, and fresh air be brought into it, and thence 
conducted to the rooms through large pipes. The warmed air 
should be let into the room at the floor, and an opening into 
an exhaust-flue, two-thirds the size of the inlet, should be 
provided at the floor for the escape of the foul air. The 
remaining one-third of the heating surface should be exposed 
in the halls and some in other parts of the house, to heat by 
direct radiation, but under no circumstance should a room or 
office be occupied which is heated exclusively by direct radiation 
from exposed steam-pipes. It is one of the worst, most un- 
healthy, killing systems in existence.'' " Probably one of the 
very best arrangements is to have a good steam furnace, with 
a large fresh-air box, letting in an abundance of air mode- 
rately warmed, and overflowing the house with this, also to 
have some direct radiation in the halls, and a bright, cheer- 
ful, open fire in the family sitting room." Two things are 
indispensable in every furnace — a large fresh-air box com- 
municating with the external atmosphere, and a large evapo- 
rating vessel. Few persons realize the necessity of supplying 
a proper amount of moisture in our stove and furnace-heated 
rooms. If it is not furnished by other means, the heated 
air will have it from the natural moisture of the skin and 
lungs, thus producing a dry, parched, feverish condition of 
the system. 



THE RESPIRATORY AND VOCAL ORGANS. 203 

425. The conditions of proper respiration require not only 
that the air be pure, but sufficient in quantity. Hence the 
chest and lungs must not be reduced in size. In children who 
have never worn close garments, the circumference of the 
chest is generally about equal to that of the body at the hips ; 
and similar proportions would exist through life if there 
were no improper pressure of the clothing. Such is the case 
with the Indian woman, whose blanket allows the free ex- 
pansion of the chest. The symmetrical statues of ancient 
sculpture bear little resemblance to the " beau ideal" of 
American notions of elegant form. The chest is often con- 
tracted in infancy, because of the mother's ignorance of the 
pliant character of the ribs and cartilages ; thus she sows the 
seeds of disease and shortens the life of her offspring. In 
later years the same result is produced by a steady and 
moderate pressure. It is in this way that the "genteel," 
tapering waist is produced. The style of dress adopted at the 
present day is a prolific cause of deformity, for deformity it 
certainly is, since the design of the human chest is not 
simply to form a connection between the upper and lower 
parts of the body, like some insects. 

426. The Chinese, by compressing the feet of female chil- 
dren, prevent their growth, so that the foot of a Chinese belle 
is not larger than the foot of an American girl of five years ; 
the American women compress their chests, so that the chest 
of an American belle is not larger than the chest of a Chinese 
girl of five years. In these respects, which country exhibits 
the greater intelligence? 

427. Individuals may have small chests from birth, this being, 
to the particular individual, natural. That like produces 
like is a general law. If the mother has a small, tapering 
waist, either hereditary or acquired, the form may be im- 
pressed on her offspring, thus illustrating the truthfulness of 
Scripture, which declares that the sins of the parent shall 
be visited upon the children unto the third and fourth 
generations. 

428. The question is often asked, Can the size of the chest 



204 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



and the volume of the lungs be increased when they have 
been once compressed ? Yes. The means to be used are> a 
full inflation of the lungs at each act of respiration, and a 
judicious exercise of them by walking in the open air, read- 
ing aloud, singing, sitting erect, and practicing appropriate 
gymnastic exercises. Unless these exercises are systematic 
and persistent, they will not afford the beneficial results de- 
sired. 

Fig. 140. Fig. 141. 




Fig. 140. A Correct Outline of the Venus de Medici, the beau ideal of female 
symmetry. 

Fig. 141. An Outline of a Well-Corseted Modern Beauty. 

One has an artificial, insect waist; the other, a natural waist. One has sloping shoul- 
ders, while the shoulders of the other are comparatively elevated, square and angular. 
The proportion of the corseted female below the waist is also a departure from the sym- 
metry of nature. 

Observation, — Persons of sedentary habits should often, 
during the day, take full, deep breaths, filling the smallest 
air-cells with air ; the shoulders should be thrown back, and 
the head held erect. 

429. Respiration is much influenced by the condition of the 
nervous system. Abstract thought, anxiety and the depress- 
ing passions diminish the contractile energy of the diaphragm 



THE RESPIRATORY AND VOCAL ORGANS. 205 

and the muscles that elevate the ribs, thus preventing the 
full inflation of the lungs. Cheerfulness, joy and all the ex- 
hilarating emotions favor free respiration, and consequently 
promote health. 

430. To resuscitate ]jersons asphyxiated from drowning, 
strangulation, electricity or breathing poisonous gases, the chest 
should be suddenly and forcibly pressed downward and back- 
ward, then the pressure suddenly discontinued. This should 
be continually repeated till a pair of bellows or some other 
means of artificial respiration can be obtained. When bel- 
lows are used, introduce the nozzle well upon the base of the 
tongue, and closely surround the mouth and nose with a 
towel, press upon the part of the neck called Adam's apple 
while introducing the air, then press upon the chest to expel 
it, thus imitating breathing. If other means of artificial 
respiration cannot be immediately obtained, let the lungs of 
the sufferer be inflated by air from the lungs of other per- 
sons present. That this air may be as pure as possible, 
the lungs should be quickly filled, and the air instantly 
expelled into the lungs of the asphyxiated person. The 
patient should be placed in pure air, and a physician pro- 
cured immediately. In case of drowning, wrap the body in 
warm flannel and place near the fire; use no friction till 
breathing is restored. 

Observation. — Inhaling the gas from burning charcoal 
placed in an open pan to warm a room, or gas from a fur- 
nace or coal stove, when the draught is imperfect, is dele- 
terious, often producing death. Care should be taken, when 
gas is used for lighting, that it is completely turned off before 
retiring to sleep. 

I 43. Comparative Pneumonology. — Respiratory Apparatus of 
Mammalia — Of Birds — Of Reptiles — Of Fishes. 

431. The Kespiratory Apparatus in all the Mammalia 
is similar to that of man, both in structure and function. 
There are similar arrangements and movements of the ribs, 
sternum, intercostal muscles and diaphragm. The lungs fill 

18 



206 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



the cavity of the thorax, and have the same general com- 
position of lobes, lobules and air-cells. 



2 




432. In Birds the lungs are confined to the back part of 
the thoracic abdominal cavity, being firmly attached to the 
ribs in their interspaces. They are not separated into lobes, 
as in the mammalia, but are lengthened, oblong and flattened 
in shape, and connected with large membranous cells scat- 
tered through every part of the body. They have the larynx, 
trachea, bronchia, pulmonary arteries, veins and capillaries, 
although much modified. 

433. The ultimate pulmonary capillaries do not form a 
network lining definitely-bounded air-cells, as in mammals, 



THE RESPIRATOKY AND VOCAL ORGANS. 



207 



but each capillary crosses an open air-space of its own. They 
interlace in every direction, forming a mass of capillaries, 
permeated everywhere by air (B, fig. 144). 



Fig. 143. 




Fig. 144. 




Fig. 143 ( Owen). The Right Lung of a Goose. — 1, A bronchus which divides into 
two tubes that open into the abdominal air-receptacles at 2, 2. 

Fig. 144 {Owen). Ideal Section of a Bird, magnified two hundred and sixty times. — 
1, A primary bronchus dividing into secondary bronchi that end in caeca, 2, 2, 2, 2, 2, 2. 
These secondary bronchi give off smaller penniform branches that ramify among the 
lobules. B, A plexus of capillary vessels. 



434. A marked modification of the respiration of birds is 
the connection of the pores of the bones and feathers with 
the bronchial tubes and air-spaces of the lungs, so that there 
is an interchange of air between the lungs, the bones and the 
investing plumage. The walls of the bones of birds are more 
cancellated than those of the mammalia. Birds consume 
more air in a given time, proportionally, than any other 
class of animals, and they soonest become asphyxiated when 
deprived of it. 



208 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



435. In Reptiles, respiration is more simple than in mam- 
mals or birds. The lungs are less lobular and more bag- 
like, extending into the abdominal cavity. Upon the walls 
of these sac-like lungs the pulmonary vessels ramify. In the 
turtle, the tortoise and the frog, the thorax is not so formed 
as to act like a suction-pump, and accordingly these animals 
swallow the air by a sort of deglutition. 



Fig. 145. 



Fig. 146. 





Fig. 145 {Owen). Tongue, Larynx and Lungs of a Frog. — 1, 2, Lungs. 3,4, Larynx. 
Fig. 146 {Owen). Heart and Lungs of a Frog. — 1, Heart. 2, Arch of the aorta. 
3. 3, Pulmonary artery. 4, 4, Pulmonary veins. 5, 5, Aorta. 6, Vena cava. 

436. In Fishes, the respiration is still more modified and more 
complicated than in reptiles. Instead of lobular or bag-like 
lungs, there are found only a series of slit-like openings, or 
arches on each side near the head, called the branchiae, or gills. 

437. The bony and cartilaginous frames of these arches, 
on the convex side, support processes. On these are many 
plates, or leaflets, covered by a delicate tessellated membrane, 
or epithelium, on which the microscopic capillary blood-ves- 
sels ramify. By this arrangement of extensive epithelial 
surface, the blood-particles are more minutely separated and 
acted upon by the air in the water. In breathing, the mouth 



THE RESPIRATORY AND VOCAL ORGANS. 



209 



and gills of a fish open alternately ; the water entering the 
mouth escapes by the openings of the gills. 



Fig. 147. 



Fig. 148. 





Fig. 147 (Owen). Section of a Branchial Arch, with a pair of processes supporting 
leaflets or plates, from a cod, magnified two hundred and sixty diameters. 1, A section 
of a branchial arch. 2, A pair of processes. 3, Branchial leaflets, or plates. The num- 
ber of leaflets in one process of the cod is about one thousand ; in the salmon, fourteen 
hundred ; in the sturgeon, sixteen hundred. 

Fig. 148 (Owen). Circulation of the Blood through the Branchial Leaflets 
(a diagram). 1, A section of a branchial arch. 2, A section of a branchial artery. 3, An 
artery sent along the outer margin of the processes, giving off capillary vessels to the 
leaflets. 4, A vein that receives the blood from the capillaries on the inner margin of 
the process after the respiratory change has been effected and returns it to the branchial 
vein (5). 

438. A remarkable feature in the organization of some 
fish is the swimming, or air-bladder, placed in the abdomen 
under the dorsal spine, communicating often with the oesoph- 
agus or stomach by a canal, permitting the escape of air 
from its interior. By a movement of the ribs, the air- 
receptacle is acted on, so that by diminishing the quantity 
of air, the specific gravity of the fish alters according to cir- 
cumstances. Fish that swim near the bottom have no air- 
bladder ; as the eel, sole and turbot. 
18* 



DIVISION IV. 

SENSORIAL APPARATUS. 

In the two preceding Divisions, the tissues and organs 
directly involved in the movements of the body, and those 
most intimately connected with the preparation and assimila- 
tion of nutrient material, have been briefly described. In 
the present Division, we consider the organs through which 
is manifested the subtle power that controls these motions 
and processes, establishes telegraphic communication between 
the several parts of the body, and brings it into important 
relations with the external world. These, taken collectively, 
we name the Sensorial Apparatus. 



CHAPTEE XI. 

NERVOUS SYSTEM. 



\ 44. Anatomy of the Nervous System. — Two Forms of Nervous 
Tissue. Classification of the Ganglia, Nerves and Commissures. Spinal 
Cord. Medulla Oblongata. Peduncles of the Cerebellum — Of the Cere- 
brum. Corpora Striata. Optici Thalami. Corpora Quadrigemina. 
Corpus Callosum. Ventricles. Hemispheres of the Cerebrum. Con- 
volutions of the Cerebrum and Cerebellum. Classification of Cerebro- 
spinal Nerves — Of Cranial Nerves — Spinal Nerves. Sympathetic Sys- 
tem. Distribution of Sympathetic Nerves. 

439. Nervous Tissue presents two formal characters, 
one, cell-like and gray in color; the other, fibrous and white. 
The former is arranged in masses called Centres or Ganglia, 
being the originating, active centres of nerve-force ; the latter, 
in threads, which are simple conductors of nerve- force, and 

210 



NERVOUS SYSTEM. 

Fig. 149. 



211 




Fig. 149. A Representation of the Brain, Spinal Cord and Spinal Nerves.- 
1, The cerebrum. 2, The cerebellum. 3, 3, Spinal cord. 4, The sciatic nerve. 

A. Distribution op the Olfactory Nerve. — 1, 2, Nerve of smell. 

B. Optic Nerve. — 15, The nerve of vision. 

C. The Gustatory Nerve. — 1, 2, 3, 4, Branches of the nerve of taste. 

D. Auditory Nerve. — 13, Nerve of hearing. 



212 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



are named Nerves when they connect the ganglia with the 
various parts of the body ; and Commissures when they con- 
nect the ganglia with each other. 

440. For convenience in study, the numerous Ganglia, 
Nerves and Commissures may be arranged in two great and 
closely-connected systems — the Cerebro- Spinal and the Sym- 
pathetic: the Cerebro-Spinal system including the series of 
ganglia within the skull and spinal column, their nerves, 
commissures and the lesser ganglia in the nerve-tracts: the 
Sympathetic system including the long chain of ganglia lying 
in front of the spinal column, their nerves, commissures and 
additional ganglia found chiefly in the abdominal cavity. 

441. The Cerebro-Spinal Axis commences w r ith that por- 
tion of nervous matter which lies within the spinal column, 
extending from the second lumbar vertebra to the base of the 
skull, and known as the Spinal Cord. It contains within 
itself the filaments of all the nerves of the external parts of 
the trunk and limbs. It is soft, and white externally, but 
grayish within, forming the longest ganglion in the system. 
The cord is nearly cylindrical and double, the two halves 

_, , rA connected by a nar- 

Fig. 150. / 

row commissure or 
bridge of the same 
substance as the 
cord, having within, 
through the entire 
length, a minute 
central canal. On 
each half are two 
slight, longitudinal 
lines, serving to dis- 
tinguish it into Ante- 
rior, Lateral and Pos- 
terior columns. As it 
enters the cavity of the skull, the cord becomes enlarged and 
receives the name of Medulla Oblonga'ta. This enlargement 
is due to the presence of an important ganglion imbedded 




Fig. 150. Transverse Section of Spinal Cord. — 1, 2, 
Spinal nerves of right and left sides, showing their two 
roots. 4, Origin of anterior root. 3, Origin of posterior 
root. 5, Ganglion of posterior root. 



NERVOUS SYSTEM. 



213 



Fig. 151. 




within, named the Ganglion of the Medulla Oblongata, and 
also to the accession of the fibres of most of the cranial 
nerves. In each of the lateral halves of the medulla ob- 
longata may be seen four principal bundles of nerve-fibres, 
ranging backward from the middle line in front as follows : 
1st, Anterior Pyramids ; 2d, the Oli- 
vary Bodies ; 3d, the Restiform Bodies ; 
and 4th, the Posterior Pyramids. These 
bodies are continuous with their cor- 
responding portions of the columns 
of the spinal cord. Many of the 
fibres of the anterior pyramids cross 
each other, bringing each side of the 
column into communication with the 
opposite side of the brain ; this cross- 
ing forms the Decussation of the An- 
terior Pyramids. Some of the fibres 
of the posterior pyramids also cross 
a little above. By the divergence 
of the restiform and posterior pyra- 
midal bodies, a somewhat broad cav- 
ity is left, which may be considered 
a widening of the central canal, and 
which receives the name of the Fourth Ventricle. 

442. Overshadowing this ventricle is a mass of nerve-sub- 
stance, called the Cerebel'lum or little brain, which is also 
double, consisting of two hemispheres. Each hemisphere, 
from its inner surface, sends out a multitude of fibres, which 
pass downward and forward toward the centre, unite into 
flattened bundles, emerge from the hemisphere, sweep across 
the base of the brain, pass up to the other hemisphere and 
spread out over its internal surface ; thus originating in one 
hemisphere, and terminating in the other. The two sets of 
fibres cross in front of the Medulla Oblongata, in the middle 
line of the base of the cerebellum, forming the bridge of the 
Cerebellum, or the Pons Varo'lii. 

At the pons, the medulla oblongata sends off from the 



Fig. 151 (Dallon). Medulla 
Oblongata of Human Brain, 
anterior view. 1, 1, Anterior 
pyramids. 2, 2, Olivary bodies. 
3, 3, Restiform bodies. 4, De- 
cussation of the anterior col- 
umns. The medulla oblongata 
is seen terminated above by the 
transverse fibres of the Pons 
Varolii. 



214 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



restiform bodies, bundles of fibres called the Inferior Peduncles 
of the Cerebellum. Passing under and among the fibres of the 
pons, and imbedding the Ganglion of the Tuber Annulare, are 
two bundles — one of fibres from the anterior pyramids and 
the front of the olivary bodies, the other from the posterior 
pyramids and the back of the olivary bodies ; as they appear 

Fig. 152. 



jff^L 




Fig. 152 (Lridy). Striated Bodies, Thalami, Quadrigeminal Body and Cehebellum. 
— 1, Quadrigeminal body. 3, Superior peduncle of the cerebellum. 4, Superior portion 
of the middle peduncle. 5, Superior portion of the crus, or leg, of the cerebrum. 6, Pos- 
terior tubercle of the thalamus. 7, Anterior tubercle. 8, Fundamental portion of the 
cerebellum. 15, Thalamus. 16, Hemispheres of the cerebellum. 17, Dentated body. 
18, Semicircular line. 19, Vein of the striated body. 20, Anterior crura of the fornix. 
21, Striated body. 22, Fifth ventricle between the layers of the pellucid septum. 



in front, they diverge, forming stalk-like bundles known as 
the Peduncles of the Cerebrum, as they seem to support the two 



NERVOUS SYSTEM. 



215 



hemispheres of the cerebrum, or brain proper, as the flower- 
stalk bears its flower. The anterior bundles pass upward to 
two large ganglia (one on each side the median line), called 
the Corpora Stria' ta, or Striated Bodies ; the posterior bundles 
also pass upward to two ganglia situated a little in front of 
the striated bodies, and named the Op'tici Thai' ami. In these 
ganglia the fibres seem to terminate, while a new set con- 
nects the ganglia with the main surface of the cerebral 
hemispheres. 

Fig. 153. 




Fig. 153 (Leidy). Section of the Brain along the Great Longitudinal Fissure.— 
1, Medulla oblongata. 2, Pons. 3, Cms of the cerebrum. 4, Arborescent appearance in 
section of the fundamental portion of the cerebellum. 5, Left hemisphere of the cere- 
bellum. 6, Inner surface of the left hemisphere of the cerebrum. 7, Corpus callosum. 
8, Pellucid septum. 9, Fornix. 10, Anterior crus of the fornix. 19, Foramen of com- 
munication between the third and lateral ventricles. 20, Optic nerve. 24, Oculo-motor 
nerve. 26, Fourth ventricle. 28, Quadrigeminal body. 29, Entrance from the third to 
to the fourth ventricle. 30, 31, 32, Anterior, middle and posterior lobes of the cerebrum. 



It will be noticed that these ganglia have an unbroken 
connection with the spinal cord through the peduncles of the 
cerebrum and the fibres of the medulla oblongata. 

Extending backward from the optic thalamus, is a body- 
divided on its upper surface into four eminences, hence called 



216 ANATOMY, PHYSIOLOGY AND HYGIENE. 

the Corpora Qaadrigemina or the Quadrigeminal body. It con- 
sists of four small ganglia, sometimes named Optic Ganglia 
(as they send nerves to the eye), which are attached to the 
peduncles of the optic thalamus, to the cerebellum and cere- 
brum and to the medulla oblongata. 

443. All the above-mentioned ganglia are variously con- 
nected with each other, with the peduncles of the cerebrum 
aud cerebellum, and, through the medulla oblongata, with 
the spinal cord. 

444. The hemispheres of the cerebrum are closely united 
in their central part by a transverse commissure, called the 
Corpus Callosum, formed by a dense band of transverse fibres 
radiating at each extremity to the inner surface of its cor- 
responding hemispheres. The corpus callosum is arched in 
shape, and about four inches in length. It forms the roof of 
a large central cavity between the two ganglia, corpora 
striata, the cavity being divided by a thin, double membrane 
(the pellucid septum) into two communicating apartments 
called the Lateral Ventricles. Each of these has for its roof 
the corpus callosum ; for its floor, the Fornix — a membrane 
continuous with the corpus callosum behind ; for its inner 
wall, the pellucid septum ; and for its outer wall, the corpus 
striatum. The floor of the lateral ventricles forms the roof 
of the Third Ventricle, which is a narrow cavity between the 
optic thalami, communicating with the fourth ventricle lying 
below and back of it, by a narrow passage-way. Hence it 
appears that the lateral ventricles, in the centre of the cere- 
brum, communicate with each other and with the-third ven- 
tricle, the third with the fourth, and the fourth w T ith the 
central canal of the spinal cord, making one unbroken com- 
munication through the whole extent. 

445. Within the hemispheres are numerous other small 
ganglia, membranes and galleries, whose description our 
present limits will not allow. 

446. The hemispheres of the cerebrum enclose all the other 
parts, in front, above and behind, like a great overshadowing 
dome. Their outer surface is of gray matter, hence they are 



NERVOUS SYSTEM. 



217 



essentially two connected ganglia, and the largest in the 
system. Each hemisphere is marked off by fissures into three 
lobes, the frontal, middle and posterior lobe or ganglion, the 
frontal being the largest, and there is a little offshoot of the 
frontal lobe, called the Olfactory. Each of these lobes has 
its surface moulded into many tortuous and complicated 
elevations of the cerebral substance, termed Convolutions, 
which are marked off from each other by secondary winding 
fissures, named Sulci; thus there is formed "one unbroken 
but undulating sheet" over the whole surface of the brain. 

Fig. 154. 




Fig. 154 represents a Convoluted Cerebral Hemisphere, a, a, The scalp turned 
down, b, b, b, The cut edge of the bones of the skull, c, The external strong membrane 
of the brain (dura mater), suspended by a hook, d, The left hemisphere of the brain. 

447. The general plan of convolutions in the two hemi- 
spheres is the same, but in detail there is want of exact sym- 
metry. It is a remarkable fact that the higher the mental 
development, the more unsymmetrical and complicated are 
the convolutions, and the deeper the depressions or Sulci. 
This is not only seen in comparing the lower animals with 
man, but in comparing different races of men. The brain 
of the " Hottentot Venus, who was no idiot," has been de- 
scribed as having the convolutions of the frontal lobe strik- 
ingly simple and regular, and as presenting an almost perfect 

19 K 



218 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



symmetry in the two hemispheres, such as is never found in 
the Caucasian race, and which much resembles that of the 
lower animals. 

Fig. 155. 




Fig. 155 (Leiibj). Base of the Brain.— 1, Anterior lobes of the cerebrum. 2, Middle 
lobes. 3, Posterior lol.es. 4, 5, Anterior and posterior extremities of the great longi- 
tudinal fissure. 11, Crura of the cerebrum. 12, Pons. 13, Medulla oblongata. 14, Pyra- 
midal bodies. 14*, Decussation of the pyramids. 15, Olivary body. 16, Restiform body. 
17. Hemispheres of the cerebellum. 19, Cms of the cerebellum. 20, Pneumogastric 
lobule of the cerebellum. 21, Fissure which accommodates the olfactory nerve (22). 23, 
Bulb of the olfactory nerve. 24, Optic commissure. 25, Oculo-motor nerve. 26, Pathetic 
nerve. 27, Trifacial nerve. 28, Abducent nerve. 29, Facial nerve. 30, Auditory nerve. 
31, Glossopharyngeal nerve. 32, Pneumogastric nerve. 33, Accessory nerve. 31, Hypo- 
glossal nerve. 

448. The cerebellum, like the cerebrum, has its hemispheres 
marked off into lobes. The lobes are highly subdivided on 
their sides and surface into thin plates or lamina, by cres- 
centic furrows or sulci. The white fibres within the cere- 



NERVOUS SYSTEM. 



219 



bellum are so arranged that, when a vertical section is taken, 
it presents the appearance of the trunk and branches of a tree, 
and hence it bears the name of Arbor Vitas (fig. 158). 

449. The parts already described, viz., the brain and spinal 
cord, constitute the Cerebro-Spinal Axis, from which proceed 



Fig. 15fi. 




THE NERVES OF THE CEREBRO-SPINAL SYSTEM. 

450. Certain of these nerves conduct nerve-force from the 
ganglia to their own distal ends in the tissues, chiefly mus- 
cular, where motion is produced ; 
other nerves carry impressions from 
their extremities to the centres ; 
the first are termed Motor y from 
their function, and Efferent from 
the direction of conduction ; the 
second are termed Sensory and 
Afferent. The anterior fibrous 
bundles of the medulla oblongata, 
passing upward to the corpora 
striata, form a Motor Tract, so dis- 
tinguished by the endowments of 
the nerves that issue from it ; the 
posterior bundles passing to the 
Thalami Optici form a Sensory 
Tract 

451. The Cerebro-Spinal nerves 
are also distinguished as Cranial 
nerves when they pass directly 
from the brain, through openings 
in the cranium ; and as Spinal 
when they issue from the vertebral 
openings of the spinal column. 
The Cranial Nerves are arranged in twelve pairs, 
named numerically, counting from before backward, or from 
their function, destination or specific character. They may 
be arranged in three groups, according to their functions, as 
Sensory, Motor and Mixed. 



Fig. 156 (Leidy). Segment of the 
Spinal Cord. — 1, Anterior median 
fissure. 2, Posterior median fissure. 
3, Posterolateral fissure. 4, Antero- 
lateral fissure. 5, Anterior column. 
6, Lateral column. 7, Posterior col- 
umn. 8, Anterior commissure. 9, 
Anterior horns of the gray sub- 
stance. 10, Posterior horns. 11, 
Gray commissure. 12, Anterior root 
of a spinal nerve springing by a 
number of filaments from the antero- 
lateral fissure. 13, Posterior root 
from postero-lateral fissure. 14, 
Ganglion on the posterior root. 15, 
Spinal nerve formed by the union 
of the two roots. 



220 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



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NERVOUS SYSTEM. 



221 



Fig. 157. 




19* 



222 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 157. Distribution of Pneumogastric Nerves. — a, Section of the brain and me- 
dulla oblongata. 6, The lateral columns of the spinal cord, c, c, The respiratory tract 
of the spinal cord, d, The tongue, e, The larynx. /, The bronchia, g. The oesophagus. 
7i, The stomach, i, The diaphragm. 1, The pneumogastric nerve. 2, The superior laryn- 
geal nerve. 3, The recurrent laryngeal nerve. (These two ramify on the larynx.) 4, 
The pulmonary plexus of the tenth nerve. 5, The cardiac plexus of the tenth nerve. 
These two plexuses supply the heart and lungs with nervous filaments. 7, The origin 
of the fourth pair of nerves, that passes to the superior oblique muscle of the eye. 8, The 
origin of the facial nerve, that is spread out on the side of the face and nose. 9, The 
origin of the glosso-pharyngeal nerve, that passes to the tongue and pharynx. 10, The 
origin of the spinal accessory nerve. 11, This nerve penetrating the sterno-mastoideus 
muscle. 12, The origin of the internal respiratory or phrenic nerve, that is seen to ramify 
on the diaphragm. 13, The origin of the external respiratory nerve, that ramifies on the 
pectoral and scaleni muscles. 



Fig. 153. 




Fig. 158. A Vertical Section of the Cerebrum, Cerebellum and Medulla Ob- 
longata, showing the relation of the cranial nerves at their origin. 1, The cerebrum. 
2, The cerebellum, with its arbor vitse represented. 3, The medulla oblongata. 4, The 
spinal cord. 5, The corpus callosum. 6, The first pair of nerves. 7, The second pair. 
8, The eye. 9, The third pair of nerves. 10, The fourth pair. 11, The fifth pair. 12, 
The sixth pair. 13, The seventh pair. 14, The eighth pair. 15, The ninth pair. 16, 
The tenth pair. 19, The eleventh pair. 18, The twelfth pair. 20, Spinal nerves. 21, 
The tentorium. 



NERVOUS SYSTEM. 



223 



453. The Spinal Nerves are arranged in thirty-one pairs, 
and (unlike the cranial nerves, excepting the Trifacial) each 
arises by two roots : an an- 
terior or Motor root spring- Fig. 159. 

ing from the anterior columns ilPP%k 

of the spinal cord, which are 

continuous with the Motor l %, I J* : , 

tract before mentioned ; and 
a, posterior or Sensitive root 
from the posterior columns 
of the spinal cord, and con- 
tinuous with the Sensory tract. 
The Sensitive roots are larger 
than the Motor, and each 
has an imbedded ganglion, 
after the formation of which 
the two roots unite into one 
trunk, forming the spinal 
nerve, which passes out of 
the spinal column through 
the intervertebral openings. 

454. The Spinal Nerves 
are divided into — 

Cervical 8 pairs. 

Dorsal 12 " 

Lumbar 5 " 13 J 

Sacral 6 " 

At some parts of their 
course certain branches of 
the nerves reunite, forming 
networks called plexuses. 
Thus the four upper cervical Fia . 159 . A Back Yiew of the Brain and 

nerves anastomose, forming Spinal Cord.— 1, The cerebrum. 2, The cere- 

y . helium. 3, The spinal cord. 4, Nerves of the 

the Cervical pleXUS, at the face> 5? T he brachial plexus of nerves. 6,7, 

side of the neck J the four 8, 9, Nerves of the arm. 10, Nerves that pass 

i "ii.i under the ribs. 11, The lumbar plexus of 

lower cervical, and the upper , ^ ' , f \ , Q 

±F nerves. 12, The sacral plexus of nerves. 13, 

dorsal, form the brachial 14, 15, 16, Nerves of the lower limbs. 




224 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



plexus (fig. 159), from which proceed six Derves which ramify 
upon the muscles and skin of the upper extremities ; the last 
dorsal and four lumbar nerves form the lumbar plexus, which 
sends off six nerves to ramify upon the muscles and skin of 
the lower extremities; the last lumbar and four upper sacral 
form the sacral plexus, which distributes nerves to the muscles 
and skin of the hip and lower extremities. 



Fig. 160. 




Fig. 160 represents the Sympathetic 
Ganglia, and their Connection with other 
Nerves, from the grand engraving of Manec, 
reduced in size. A, A, A, The semilunar 
ganglion and solar plexus, situated below 
the diaphragm and behind the stomach. 
This ganglion is situated in the region (pit 
of the stomach) where a blow gives severe 
suffering. D, D, D, The thoracic (chest) 
ganglia, ten or eleven in number. E, E, 
The external and internal branches of the 
thoracic ganglia. G, H, The right and left 
coronary plexus, situated upon the heart. 
I, N, Q, The inferior, middle and superior 
cervical (neck) ganglia. 1. The renal plexus 
of nerves that surrounds the kidneys. 2, The 
lumbar (loin) ganglion. 3, Their internal 
blanches. 4, Their external branches. 5, 
The aortic plexus of nerves that lies upon 
the aorta. The other letters and figures re- 
present nerves that connect important organs 
and nerves with the sympathetic ganglia. 



THE SYMPATHETIC NERVOUS SYSTEM. 

455. The Sympathetic system, like the Cerebro Spinal, is 
double, consisting of two chains of ganglia, one on each side 



NERVOUS SYSTEM, 225 

of the spinal column, running through the deep parts of the 
neck, into the chest and abdomen. These ganglia communi- 
cate with each other, with the spinal cord and with the inter- 
nal organs — as the heart, lungs, stomach, liver, pancreas, 
intestines and kidneys. In the neck and chest the ganglia 
are arranged in pairs ; those of the neck are three in number 
and the largest of the system ; those of the chest, twelve in 
number, a ganglion resting upon the head of each rib ; in the 
ab,domen the arrangement is irregular. 

456. A peculiarity of the Sympathetic nerves is, that they 
follow the distribution of the blood-vessels. Starting from the 
heart, they envelop the large vessels with a close network, 
called the Arterial 'plexus; and in the abdomen, behind the 
stomach, the large blood-vessels are surrounded by many 
small ganglia, all united by networks of fibres called the 
solar plexus, because the other plexuses of the abdomen 
radiate from it, like the rays diverging from the sun. In all 
parts of the body, these nerves accompany the arteries which 
supply the different organs, and form networks around them 
which take the names of the organs, as the hepatic plexus, 
splenic plexus, mesenteric plexus, etc. 

\ 45. Histology of the Nervous System. — Three Microscopic 
Elements of Nerve-Tissue. Nerve- Cells. Nerve-Fibres. Membranes 
of Cerebro-Spinal System. 

457. Nervous Tissue is composed of three microscopic 
elements — Nerve- Cells, or Ganglionic Corpuscles } White or 
Tubular Fibres, and Gray or Gelatinous Fibres, 

458. The Nerve-Cells are nucleated cells ; that is, vesic- 
ular matter containing, besides a pulpy substance, an eccen- 
tric, roundish body, or nucleus, enclosing one or more nucleoli 
surrounded by colored granules (32). These nerve-cells have 
various branches or offsets starting from any part of the cell- 
wall and completely continuous with it and with the con- 
tents of the cell itself. The branches connect the cells with 
each other, and also with the nerve-fibres. Their number 
varies from one to twenty, and the cells are accordingly dis- 

K* 



226 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 161. 




tinguished as unipolar, bipolar and multipolar (fig. 16). A 
collection of nerve-cells constitutes the essential part of a 
Ganglion. They are imbedded in a 
matrix of fine, soft, granular matter, 
and variously mingled and interwoven 
with multitudes of fibres. Composed 
of such masses, do we find the whole 
convoluted surface of the brain, the 
thalami optici, the corpora striata, the 
quadrigeminal body and some other 
minute bodies ; from these, one un- 
broken, gray tract may be traced 
through the interior of the peduncles of 
the brain, the interior of the medulla ob- 
longata and of the spinal cord (fig. 164). 
The various ganglia of the sympathetic 
system are also of the same substance. 

459. The White or Tubular Fibres, or the ultimate 
nerve-filaments, consist of an outer, structureless membrane en- 
closing a layer of trans- 
parent fluid fat, or me- 
dullary matter, within 
which is a firmer part 
— a gray, ribbon-like 
thread — called the cen- 
tral band-axis, or the 
axis cylinder. This is 
identical in structure 

with the processes of the nerve-cells with which it is con- 
tinuous, and is very important, as it is sometimes the only 
part of the nerve-fibre left within the structureless sheath ; 
thus constituting the so-called pale, non-medullated nerve- 
fibre. As the medullary matter encloses the band-axis, it is 
often, though improperly, called the medullary sheath. 

460. The nerve -filaments are distributed to the skin, 
muscles and glandular organs, in all parts of the body. 
From these points they approach each other, uniting into 



Fig. 1G1 (Leidy). Portion 
of Gray Substance, from 
the Exterior of the Cere- 
bellum. — 1, Two nerve-cells 
with bipolar prolongations. 
2, Granular matter. 3, Nu- 
clear bodies. 4, Nerve-fibres. 



Fig. 162. 




Fig. 162. Nerve-Filaments, decussing with their 
sheath. 



NERVOUS SYSTEM. 



227 



little bundles or fibres, and then into larger bundles, till they 
are of sufficient size to be seen by the naked eye, when they 
constitute a nerve. The filaments do not blend with each 
other, but lie in simple juxtaposition, each retaining a com- 
plete individuality from its origin to its termination. Like 
the fibres of a muscle, they are bound together and protected 
by a covering of areolar tissue, called its Neurilem! 'a, or sheath, 
which also contains the blood-vessels for the nutrition of the 
nerve. The filaments become gradually finer toward their 
outer extremities, till at length the sheath, medullary por- 
tion and band-axis become undistinguishable. Their mode 
of termination is uncertain, though the sensory nerves, at 
least, seem to have free extremities. 

Fig. 163. 




Fig. 163. Diagram of Human Brain, in Vertical Section, showing the situation of 
the different ganglia and the course of the fibres. 1, Olfactory ganglion. 2, Hemisphere. 
3, Corpus striatum. 4, Optic thalamus. 5, Tubercula quadrigemina. 6, Cerebellum. 
7, G-anglion of tuber annulare. 8, Ganglion of medulla oblongata. 

461. The tubular fibres compose the white parts of the 
brain and the spinal cord ; the chief substance of the nerves ; 
and also pass into and mix with the gray substance of the 
brain, cord and all the ganglia. They vary in size, being 
finest of all in the superficial layers of the brain, fine in the 
nerves of special sense and in the ganglia, larger in the fore 
part of the spinal cord, and largest in the motor nerves. 

462. Besides the White tubular fibres, there are found, 



228 ANATOMY, PHYSIOLOGY AND HYGIENE. 

chiefly in the Sympathetic System, Gray or Gelatinous 
Fibres, which are flattened, more minute than the white fibres, 
and greatly resembling their band-axis. Some have considered 
these but a form of connective tissue, but whether they be so 
considered, or as true nervous elements, they seem to be pro- 
duced by the coalescence of elongated nucleated cells, the 
contents of which, as the cells enlarge, become soft and finely 
granular, while the nuclei appear wider and wider apart. 

463. The Membranes of the Cerebro-Spinal System are 
four in number — the Dura Mater, the Pla Mater, the Arach- 
noid Membrane and the Epen'dyma. The Dura Mater is a 
tough, fibrous membrane lining the bony walls of the skull 
and spinal column, forming their periosteum. The Pia Mater 
is another fibrous and very vascular membrane which closely 
invests the brain and spinal cord, and sends processes into all 
their fissures. The inner surface of the dura mater, and the 
outer surface of the pia mater, each become very delicate in 
structure and are lined with an epithelium : this gossamer mem- 
brane is named the Arachnoid Membrane. Its two layers unite 
at many points, thus forming closed sacs, which, like other 
serous membranes, secrete a fluid called the arachnoid fluid. 

464. The dura mater not only firmly invests the brain and 
spinal cord, but sends off supporting partitions — that which de- 
scends between the hemispheres of the cerebrum being called 
the Cerebral Falx; that between the hemispheres of the cere- 
bellum, the Cerebellar Falx; and that between the cerebrum 
and cerebellum, the Tentorium. Through separations in the 
layers of the dura mater, channels are formed, performing 
the office of veins : they are named Sinuses of the Dura Mater, 
and are lined with a continuation of the ordinary epithelium 
of blood-vessels. The dura mater also furnishes the areolar 
sheaths to the several cranial and spinal nerves ; therefore it 
is continuous from the lining of the cranium to the extremity 
of the nerves in the different parts of the body. 

465. The Ependyma is a delicate, transparent, serous mem- 
brane, lining the ventricles of the brain and the central canal 
of the spinal cord. 



NERVOUS SYSTEM. 229 

\ 46. Physiology of the Nervous System. — Man's Compound 
Nature. Relation of the Nervous System to this Nature. The Bank 
of the Nervous System. Relation of the Nervous Centres to the Sensitive 
and Motor Nerves. Classification of the Centres. System of Dependen- 
cies, General Function of the Organic Centres. Their Modes of Reflex 
Action. Peculiarity of Sympathetic Action. Functions of the Reflex or 
Spinal Centres. Their Acquired Action, and the Theory Explaining it. 
tactical Importance of the Automatic Tendency produced by Repeti- 
tion and Association. Character of the Sensational Centres and their 
' Action. Internal Stimuli to the Activity of these Centres. Functions 
of the Ideational Centres. Ideas Suggested by the Same Object different 
in Different Individuals. Various Manifestations of Reflex Action in 
the Ideational Centres. Emotional Character of these Centres. Voli- 
tional Character. Relation of the Emotions to the Will. Influence of the 
Physical Nature for Good or for Evil. The Language of the Muscles. 

466. At different periods of the world's history, many dif- 
ferent opinions have prevailed concerning the respective 
existence of body and soul, and their relations to each other. 
The pagan Greek included all under the one word (po^yj and 
the Roman under that of anima, which was almost " equally 
applicable to the vegetative life of a cabbage, the animal life 
of a sheep, and the spiritual life of an apostle." During the 
fifth century before the Christian era, Anaxagoras advanced 
a shadowy idea of man's compound nature, which at the day- 
dawn of Christianity assumed a clear and definite outline. 
At length philosopher and Christian advocated the supremacy 
of the immaterial nature over the material, and eventually 
regarded their interests as antagonistic. The body was deemed 
the source of all evil — the work of the Prince of Darkness. 
At the present day, more than at any former period, efforts 
are being made to rightly balance the two natures, and yet 
many seem to regard the body as a gloomy prison-house in 
which God has shut us up, rather than as a beautiful " temple " 
in which the mind and soul may dwell as priest and priestess, 
using all its appointments in rendering service to the Lord 
of the temple. 

467. The Nervous System is the border-land where the 
material touches the immaterial. It possesses that highest 

20 



230 ANATOMY, PHYSIOLOGY AND HYGIENE. 

refinement of physical organization through which the mind 
may manifest itself, and by means of which it may control 
and bring into service, not only the various organs of the 
body, but other matter more external and remote. 

468. The organisms heretofore described have no inherent 
active power, but are entirely dependent upon the nervous 
system : thus, the bones are dependent for movement upon 
the contractility of the muscles ; this contractility, upon the 
stimulus of the nerves ; this stimulus, upon the energetic 
action of the nerve-centres ; and these centres are graded in 
rank and measurably dependent, the lowest upon the next 
higher, and so on to the highest, or convoluted centres of the 
hemispheres. 

469. In their function, the nervous centres are intermediate 
between the sensitive and motor fibres ; as the sensitive 
fibres, being acted upon at their distal extremities, convey 
impressions inward to the centre; and the motor fibres, being 
acted upon at the centres, convey nerve-force outward, and 
produce motion at their distal extremities. Let any part of 
the surface of the body be touched by a hot iron, and mus- 
cular contraction instantly follows ; but there has been time 
enough for the sensation of pain to be conveyed to the nervous 
centre, and for an impulse to be sent from that centre to the 
muscles : such action is called the Reflex Action of the Nervous 
System. By this means a communication is established be- 
tween the different organs. This communication is never 
direct, but from one organ inward to the nervous centre, 
then outward to another organ : so are the different functions 
associated and exercised for the common good of the whole. 

470. In dealing with the functions of the Nervous System 
we adopt the following classification of the Nervous Centres : 
viz. — 1st, The Primary or Ideational Centres, comprising the 
gray matter of the convolutions of the hemispheres (446) ; 
2d, The Secondary or Sensational Centres, comprising the 
gray matter between the floors of the lateral ventricles and 
the decussation of the pyramids (442) ; 3d, The Tertiary 
Centres, or Centres of Reflex Action, comprising the gray 



NERVOUS SYSTEM. 231 

matter of the spinal cord (441) ; 4th, The Quarternary or 
Organic Centres, comprising the gray matter of the Sym- 
pathetic System (455). 

471. The arrangement of this system of centres is like that 
of a well-ordered body politic. Each distinct department, or 
nerve-centre, acts independently within certain limits, but 
beyond these limits it is subordinate to the next higher: 
thus, the Organic Centres are subordinate to the Reflex or 
Spinal Centres ; the Reflex, to the Sensorial ; and all, to the 
Ideational or Supreme Centres. In each centre the indi- 
vidual cells probably differ in rank, some having a higher 
dignity, some a lower, but each its special appointment, its 
assigned duty. Such would be the inference from their 
varied form, color, size, and mode of branching. There are 
probably important differences of chemical constitution and 
action, but of this we have no means of proof. There is, 
then, reason for supposing that from the lowliest cell in the 
Organic centres, to that of highest rank in the Ideational, 
there is a long series of dependencies, and, so nice is the ad- 
justment, that if one fails to conform to the laws of the 
organization the others must suffer. Slight disturbances may 
take place in the lower centres without the knowledge of the 
Supreme Authority, but any serious matter beyond their con- 
trol is early reported ; this is the meaning of pain, weariness, 
etc. If the warning is disregarded at headquarters, there is 
liability to an open rebellion that will shake the system to 
its foundations, and not unlikely result in its complete over- 
throw. "The well-being and power of the higher individuals 
are entirely dependent upon the well-being and contentment 
of the humbler workers, which do so great a part of the daily 
work of life." 

472. The Organic or Sympathetic Centres are not 
well understood, but the distribution of their nerves would 
indicate that they exercise a controlling influence over the 
involuntary functions of digestion, absorption, circulation 
and assimilation. From the fact that these nerves reach 
their ultimate destination supported on the arterial vessels, 



232 ANATOMY, PHYSIOLOGY AND HYGIENE. 

it is probable that their influence is exerted through a certain 
control over the muscular coat of the heart and arteries, thus 
hastening or retarding the course of the blood, and increasing 
or diminishing its quantity in various organs. Thus the 
functions of nutrition, secretion, etc., depending so much 
upon the state of the circulation, are made to sympathize 
with each other very closely; hence the name, " Sympathetic'' 
System (456). 

473. The organic centres being connected with the various 
organs by sensitive and motor nerves, are capable of an inde- 
pendent reflex action. They are also connected with the 
cerebrospinal system, and are more or less assisted by and 
subordinate to it. In health the brain takes no cognizance 
of their action ; when diseased, however, the centres report 
to the highest authority by means of cramps and other 
severely acute pains. In its normal action, a centre seems 
to expend only so much force as is disposed of by the motor 
nerves ; in diseased action there is a surplus, which is con- 
veyed to the next higher centre, to be disposed of by its motor 
nerves ; if there is still a surplus, it passes on as before. 

474. There are three kinds of reflex action taking place 
either wholly or partially through the Sympathetic System ; 
viz. — 1st, The reflex action from the internal organs to the 
voluntary muscles and sensitive surfaces : examples are seen 
in the convulsions of children, caused by the irritation of un- 
digested food in the intestines ; and in adults, in the attacks 
of temporary blindness or confused vision so often accompany- 
ing indigestion. 2d, The reflex action from the sensitive sur- 
faces to the involuntary muscles and the internal organs; as 
mental and moral impressions received by the senses disturb 
the motions of the heart and affect the circulation, digestion 
and secretion ; disagreeable sights or odors produce nausea 
and other functional derangements. 3d, The reflex action 
between the internal organs ; as the associated action of the 
stomach, liver, etc. The variation in the capillary circula- 
tion of the abdominal viscera, according as they are active 
or inactive, is probably referable to a similar influence. 



NERVOUS SYSTEM. 233 

475. One marked peculiarity of the Sympathetic System is, 
that its nerves and ganglia act with much less rapidity than 
those of the Cerebro-Spinal System ; hence, inflammation of 
the internal organs is not manifest for several hours after the 
application of the exciting cause ; as the effects of a chill or 
cold do not usually follow immediately after the exposure. 
Because of this tardy action, the effect remains long after the 
cause is removed. A very beautiful example of the slow 
action of the sympathetic nerves is seen in the movements 
of the iris of the eye. The ciliary nerves controlling these 
movements originate in the brain, but pass through, and are 
affected by, a sympathetic ganglion. In passing from the 
dazzling sunshine into the house, we are scarcely able to 
distinguish objects about us, and some minutes are often re- 
quired to adapt the iris to the less amount of light ; and the 
same slow movement is evident in passing from a less degree 
of light to a greater. Were these nerves purely cerebro- 
spinal, the action would take place instantly. 

476. The Tertiary, Reflex or Spinal Centres. The 
white, tubular substance of the spinal cord connects the 
muscles and integuments below with the brain above, and 
thus assists in the production of conscious sensation and 
voluntary motion. The gray matter forms nerve-centres, 
which exert a general protective influence over the whole body. 
They preside over the involuntary movements of the limbs and 
trunk; if a finger touch a heated surface, it is suddenly with- 
drawn, and that without effort of the will, and often in oppo- 
sition to it. The same movement takes place upon tickling 
the foot of a person asleep. They regulate the action of the 
sphincter muscles, as in the rectum and bladder. They exer- 
cise a certain control over the changes of secretion, nutrition, etc, 
as is manifest in cases of disease. Thus we see that many 
human activities are performed by the reflex action of the 
spinal centres, inherent in their natural constitution. 

477. They are, however, capable of an acquired reflex 
action, which is matured through experience. An act or 
an association of acts becomes easier to them by repetition. 

20* 



234 ANATOMY, PHYSIOLOGY AND HYGIENE. 

This acquired power of reflex action has been accounted for 
by a theory* which, is at least beautifully illustrative of the 
facts in the case. Every display of energy in the nerve-cells 
causes a change or waste of nervous element which is re- 
paired by nutrition. This theory assumes that the character 
of the waste determines the character of the deposit; that the 
particle deposited is necessarily endowed according to the 
particular kind of activity manifested, and that this endow- 
ment inclines the particle to the same kind of activity again. 
By each repetition, the tendency becomes stronger and more 
definite, till, after a longer or shorter series of repetitions, the 
action becomes automatic, 

478. When a certain class of movements have, after many 
voluntary efforts, become associated, they become perceptibly 
more and more easy. Walking is at first a very conscious 
and voluntary act ; but it may become so far reflex and 
automatic that one in a profound abstraction may continue 
to walk without being at all conscious where he is going, and 
when he wakes from his revery may find himself in some 
other place than that which he intended to visit. Multi- 
tudes of our daily acts are the result of this acquired reflex 
action of the spinal centres. The wisdom of such an arrange- 
ment is very evident, for but little could be accomplished if 
acts became no easier by repetition and association. Con- 
scious efforts of the will soon produce exhaustion, while the 
automatic acts of which we are speaking occasion compara- 
tively little weariness. We often say of certain rounds of 
duties that they do not weary us, for we are accustomed to 
them. In speaking of this acquired power of which the 
spinal centres are capable, Dr. Maudsley says, "Like the 
brain, the spinal cord has its memory. A spinal cord without 
memory would be an idiotic spinal cord, incapable of culture 
—a degenerate nervous centre in which the organization of ' 
special faculties could not take place. It is the lesson of a 
good education so consciously to exercise it in reference to 

* Dr. Maudslev. 



NERVOUS SYSTEM. 235 

its surroundings that it shall act automatically in accordance 
with the relations of the individual in his particular walk 
of life." 

479. The Sensational Centres, including the gray mat- 
ter of the medulla oblongata, and of the base of the brain as 
far as the lateral ventricles, consist chiefly of the nervous 
centres of the higher or special senses, as sight, hearing (442), 
etc. Any one of these senses is quickly destroyed by destroy- 
ing its ganglion : the loss of the quadrigeminal body destroys 
the sight as effectually as putting out the eyes. That these 
centres have an independent reflex action may be seen by 
the involuntary closure of the eyelid when a strong light 
falls upon the eye, or by the involuntary contortions of the 
face when an article is sour or bitter to the taste. These are 
examples of natural reflex action, but, like the spinal cord, 
these centres are capable of an acquired reflex action ; as in 
the articulation of words upon seeing their signs ; adapting 
the movements of the body to the rhythm of music, in 
dancing, marching, etc. Most of the sensations of the special 
senses become clear and definite only after a long course of 
training ; for instance, the visual sensation of the adult is a 
very different matter from that of the child whose eyes have 
recently opened upon the world. " The sensation of the culti- 
vated sense thus sums up, as it were, a thousand experiences, 
as one word often contains the accumulated acquisitions of 
generations." 

480. In speaking of the acquired reflex action of the spinal 
centres, we referred to the theory that a relic, or residuum, of 
every activity remained in the nerve-cell as a special endow- 
ment; that perhaps the character of the activity determined 
the character of the nutritive deposit. This theory is equally 
applicable to the sensational centres, and equally illustrative 
of the certain fact that acts of this class are rendered easier 
by repetition. 

481. The sensational centres are excited to activity not 
only by impressions from the organs of the special senses, 
but by sensations from within the body, both from the organic 



236 ANATOMY, PHYSIOLOGY AND HYGIENE. 

and ideational centres. Of the former, examples are afforded 
when the higher nervous centres are weakened by disease, or 
when the organic stimuli have an unnatural activity, as is 
the case with the intemperate man. 

482. The Ideational Centres seem to have the power 
of fashioning into ideas the impressions received by the sensa- 
tional centres. When the various properties of an object are 
presented by the different senses, these centres reject the un- 
essential, and, selecting the essential, mould them into an 
organic unity, or idea. By means of the sensorial centres 
and nerves, we may gain perceptions or impressions of the 
qualities of a rose, but these would be isolated, and we should 
have no clear and definite idea of the rose, without the mould- 
ing and vivifying influences of the ideational centres. 

483. Different persons obtain very different ideas of the 
same object ; the character of the idea being dependent upon 
the character of the organization both of the sensational and 
ideational centres, and the character of the organization upon 
natural endowment, or inherited organization, and also upon 
the education received. 

484. The ideational centres, like those already described, 
are capable of an independent, reflex action, which may be 
manifested in different ways : 1st, This may take place 
through the motor tract, thus giving rise to what have been 
named ideomotor movements. This energy may be exerted 
either upon the voluntary or involuntary muscles, and in the 
former case either with or without consciousness : the idea 
that vomiting must take place when a qualmish feeling exists 
will hasten or even produce vomiting, affording an example 
of the reflex action of an idea upon the involuntary muscles, 
conformable to what has been said of the subordination of 
the organic nervous centres to those of the cerebro-spinal 
system. Examples of the reflex action of ideas upon our 
voluntary muscles are seen every hour of our waking life ; 
these may be unconscious, as is seen in most persons who 
talk to themselves, or they may be consciotis, and yet without 
the intervention of the will, as when a quick-tempered indi- 



NERVOUS SYSTEM. 237 

vidual quickly resents an insult by a blow. 2d, The reflex 
action of an ideational nerve-cell may not only operate 
downward upon the muscular system, but downward upon 
the sensory centres : the idea of a nauseous taste may excite 
the sensation to such a degree as to produce vomiting. The 
action of ideas upon our sensory ganglia is indeed a regular 
part of our mental life, for the co-operation of sensory activity 
is necessary to clear conception and representation, and by it 
we may see our own ideas as actual images. Those great 
writers who delight us with their vivid descriptions of scenery 
or events possess this power in a high degree. 3d, Another 
very important reflex action of these centres is that which 
modifies the secretions and nutrition : a flow of saliva may be 
produced by the thought of food, or a flow of tears by a sym- 
pathetic idea. 4th, There may be in these centres a reflex 
action among the cells themselves. One cell reacts to a 
stimulus from a neighboring cell, then transfers or reflects 
this energy to another. This may be the condition of activity 
among these cells during that process of the mind which we 
call Reflection. 

485. These ideational centres are also the seat of the Emo- 
tions. When an idea is attended with some feeling, either 
pleasant or unpleasant, it is so far Emotional; and when the 
feeling preponderates, the idea is obscured, and the state of 
mind is then called an Emotion, or, when rising above the 
ordinary degree and becoming impatient of restraint, a Pas- 
sion. The capacity for emotion depends essentially upon the 
range and vigor of ideas. The man of great strength of 
mind, as a Milton or Napoleon, is capable of deeper emotion 
than the man of dwarfed and puny intellect. Indeed, just here 
lies, in no small degree, the secret of his superior power. 
The same stimulus may at one time produce simply an idea, 
and at another time an emotion, according to the condition 
of the nerve-cells. 

486. Every centre of idea is also a centre of Volitionary re- 
action. When an idea acts directly downward, we call the 
effect ideomotor ; but when there is deliberation or reflection 



238 ANATOMY, PHYSIOLOGY AND HYGIENE. 

delaying the action, and it afterward takes place downward, 
we call the effect volitional. Volition is also exercised in pre- 
venting as well as in producing an action. 

487. The exercise of the Will is the highest energy of 
which the supreme centres are capable. Within certain 
limits, the ideas and emotions are subject to its control. 
Suppose a being endowed with the intellectual and emotional 
natures, but not with the will : though possessing the intelli- 
gence of a man, his capacities for action would be inferior to 
those of the brutes, for, like them, his actions would be the 
result of mere sensational impulses, and yet he would be 
destitute of that natural guide of brutes which we call in- 
stinct This represents the wretched condition of a man 
whose will is by any means so enfeebled that it fails to con- 
trol the mental and physical powers. 

488. The poiver of the will depends both upon the inherited 
organization and also upon the training it has received, for 
volitions, like sensations and ideas, become more easy and 
definite by repetition. A naturally weak will may be greatly 
strengthened by due care and training. According to the 
theory before mentioned, each volition leaves its relic, trace 
or residuum which inclines the portion of nerve-element 
exercised to a like activity again. If we accustom ourselves 
to decide promptly, to act energetically and to carry out our 
purposes in the many smaller and less important affairs of 
life, we gain a power of will which may be carried into 
higher departments of action and into circumstances of 
greater embarrassment and difficulty. 

489. The Will bears very important relations to the Emo- 
tions. If they are allowed to react independently, as is their 
natural tendency, they weaken the will ; if duly controlled 
and co-ordinated, they strengthen it. The passionate nature 
of the child may, by proper training, become a potent force 
for good in after years, "giving a white heat, as it were, 
to the expression of thought, an intensity to the will/' 
Untrained, it will become a no less potent force for evil, 
and the individual under the mastery of his passions will 



NERVOUS SYSTEM. 239 

be tossed about as helplessly as a boat in the rapids of 
Niagara. 

490. The free action of the will requires an unimpeded 
association of ideas, and the ease and completeness of such an 
association depends upon the condition of nervous element, 
very slight disorders of which declare themselves in the de- 
terioration of the will-power. As in the spinal centres dis- 
turbance of the nerve-element weakens their control over 
movements, so in the ideational centres disordered nerve- 
element is quickly manifested in the loss of will-power ; and 
as in great disorder of the spinal centres all co-ordinating 
power is lost and convulsions ensue, so in great disorders 
of the ideational centres all co-ordinating power over the 
thoughts and feelings is lost, convulsive reactions of the cells 
take place, and the individual becomes insane, 

491. We have seen that the mind is closely united and yet 
distinct from the material organ through which it acts — de- 
pendent for its manifestations, but independent in essence. 
So intimate is the union, that the body exercises a powerful 
influence in leading us upward into a true and higher life, or 
downward into a low and sensual existence. What this in- 
fluence shall be depends somewhat upon inherited organiza- 
tion, but more upon education. Accepting the theory already 
advanced as at least illustrative, we see that if the thoughts, 
feelings and volitions are pure and true and good, their im- 
pressions or residua remaining in the nerve-cells are of the 
same character, and tend to give a right direction to the 
future activities of these cells. If the thoughts, feelings and 
volitions are evil in nature, the impressions or residua will 
also be evil, inclining to evil activities in the future. When 
we resist a temptation to wrong action, then we not only 
avoid the particular evil, but lay up that which will render 
the next resistance easier and more natural. If we yield to 
the temptation, we are not only guilty of the particular 
wrong, but lay up that which will make resistance more diffi- 
cult or yielding more easy and natural for the future. When 
a man sets his heart to do right, all his physical being struggles 



240 ANATOMY, PHYSIOLOGY AND HYGIENE. 

to give him aid ; and when he sets his heart to do wrong, its 
energies are expended in dragging him downward. 

492. The visible impress which the workings of the mind 
leave upon the body is worthy our notice. The character of 
the man is declared by the lines of his muscles, which tell no 
lies. Especially is this true of the muscles of the face. Let 
him narrow his soul by penuriousness, become the victim of 
rasping jealousy, wear the nettles of envy against his heart, 
or be the slave of defiling lust, and in spite of any natural 
comeliness or studied concealment, his true character will be 
proclaimed to all who have learned aught of the language 
of the muscles. " Be sure your sin will find you out/' says 
He who has made the fleshly lineaments to reveal the most 
hidden vice. The more secret the viciousness, the deeper is 
the impress. But if the spirit of evil thus leaves the traces 
of its blackened pen upon the face, the spirit of goodness 
writes thereon in no less legible characters of light. Purity 
of heart, nobleness of purpose, restful ness of soul, soften, 
irradiate, spiritualize the outer man, giving a higher beauty 
than that of form or complexion, even to him who is 
wrinkled by years, bowed by infirmity and scarred by the 
battles of life. 



$ 47. Hygiene of the Nervous System. — Two Classes of Agencies 
Affecting the Health of the Nervous System. Natural Heritage. Im- 
portance of the Physical Agency — Air — Diet — Exercise and Sleep. 
The Effect of Mental Impressions on the Body. Mental Exercise. Re- 
creation and Amusement. Harmonious Development of the Different 
Mental Powers. 

493. We have seen that different organs of the body are 
entirely dependent for functional action upon the stimulus 
afforded by the nervous system ; and since this is the mate- 
rial organization through which the mind acts, we are led to 
the inevitable conclusion that the physical condition of this 
system must affect, more or less, the mental manifestations. 
It becomes, then, a matter of primary importance that we 



NERVOUS SYSTEM. 241 

understand the conditions essential to the health of this sys- 
tem, especially as suffering from nervous disease exceeds that 
of other diseases, as the delicacy of the organization exceeds 
that of other organizations of the body. 

494. In considering the hygiene of the nervous system, it 
is necessary to have reference both to physical and mental 
agencies. The highest health and vigor of the nervous sys- 
tem doubtless require — 1st, A sound nervous organization 
by, inheritance. 2d, A nutrition equal to the demands of re- 
pair and growth. 3d, The harmonious action of the various 
mental powers. 

495. 1st, A Sound Organization by Inheritance. 
" Each of us is only the footing-up of a double column of 
figures that goes back to the first pair," is the striking ex- 
pression of a great truth. Every-day observation shows that 
children inherit not only the features, but the physical, 
mental and moral constitution of their parents. Even those 
utterly ignorant of the laws of transmission are wont to 
estimate the child according to its family ; favorably, if of a 
4 'good family'' or "good blood;" unfavorably, if of a "bad 
family" or "bad blood." 

Every formation of body, internal and external, all intel- 
lectual endowments and aptitudes, and all moral qualities, 
are or may be transmissible from parent to child. If one 
generation is missed, the qualities may appear in the next 
generation. It is important to notice that not only the 
natural constitution of the parents may be inherited, but their 
acquired habits of life, whether virtuous or vicious, but espe- 
cially is this true of vice. Even when the identical vice does 
not appear, there is a morbid organization and a tendency to 
some vice akin to it. Not only is the evil tendency trans- 
mitted, but what was the simple practice, the voluntarily 
adopted and cherished vice of the parent, becomes the pas- 
sion, the overpowering impulse of the child. 

496. M. Morel sketches the history of four generations 
as follows : " First Generation. — The father was a habitual 
drunkard, and was killed in a public-house brawl. Second 

21 L 



242 ANATOMY, PHYSIOLOGY AND HYGIENE. 

Generation. — The son inherited his father's habits, which 
gave rise to attacks of mania, terminating in paralysis and 
death. Third Generation. — The grandson was strictly sober, 
but full of hypochondriacal and imaginary fears of persecu- 
tions, etc., and had homicidal tendencies. Fourth Genera- 
tion. — The fourth in descent had very limited intelligence, 
and had an attack of madness when sixteen years old, termi- 
nating in stupidity nearly amounting to idiocy ; with him the 
race probably becomes extinct." 

497. Says a learned physician, after long and close ob- 
servation of the evil effects of tobacco : " If the evil ended 
with the individual who, by the indulgence of a pernicious 
custom, injures his own health and impairs his faculties of 
mind and body, he might be left to his enjoyment, his/oo^s 
paradise, unmolested. This, however, is not the case. In no 
instance is the sin of the father more strikingly visited upon 
the children than the sin of tobacco-smoking. The enerva- 
tion, the hysteria, the insanity, the dwarfish deformities, the 
consumption, the suffering lives and early deaths of the chil- 
dren of inveterate smokers bear ample testimony to the 
feebleness and unsoundness of the constitution transmitted 
by this pernicious habit." 

498. Should we trace the effects of the whole list of vices, 
it would be with equally sad results ; even of the great love 
of money-getting, the celebrated Dr. Maudsley says : " I can- 
not but think, after what I have seen, that the extreme pas- 
sion for getting rich, absorbing the whole energies of a life, 
does predispose to mental degeneration in the offspring, either 
to moral defect, or to moral and intellectual deficiency, or to 
outbreaks of insanity." 

499. Any kind of nervous disease in the parents, whether 
natural or acquired, seems to predispose to innate feeble- 
ness in the child. From this instability of nervous ele- 
ment, the slightest irritation often produces convulsions 
in the young child and loss of equilibrium in the adult. 
Such a natural constitution may be improved by a judi- 
cious education and strict obedience to physical and men- 



NERVOUS SYSTEM. 243 

tal laws ; but the original defect can never be entirely- 
removed. 

500. 2d, A Nutrition equal to the Demands of 
Repair and Growth. The relation of the nervous centres 
to the blood is the same in kind as that between other parts 
of the body and their blood-supply. Great waste is produced 
by nervous action ; hence, the centres are very largely sup- 
plied with blood-vessels, especially the Ideational centres. 
The activity of ideas is largely dependent upon the active 
flow of blood to the nerve-cells. Activity of thought invites 
the blood which, in turn, is so necessary to activity. The 
nerve-centres, then, must be supplied with the proper quality 
and quantity of blood ; hence, whatever deteriorates the 
blood impairs the health of the nervous system. It is evi- 
dent, then, that — 

501. The nervous system may he impaired by impure air. 
Everybody knows that bad air injures the lungs, but few 
realize that, on the whole, it injures the brain still more. 
As the nerve-tissue is the most delicate part of the body, 
it soonest feels the evil effects of imperfectly oxygenated 
blood. (See Respiration.) 

502. The nervous system may be impaired by improper diet 
We are wont to believe that improper diet may affect the 
digestive organs, but seldom consider the mental and moral 
effects of such diet. Improper food poisons the blood, and 
thus the nerve-centres are cheated of their nutriment and 
also poisoned ; hence, the ideas become confused, the emo- 
tions morbid and the will weakened. The whole man is 
crippled, physically, mentally and morally. It is an indis- 
putable fact that bad bread, for instance, may thus have a 
very immoral influence. Those much engaged in mental 
labor suffer most from bad diet. No teacher can teach well, 
no lawyer can plead well, no physician can practice well, no 
minister can preach well, who habitually takes improper 
food. (See Digestion.) 

503. If such be the effect of improper food, what shall we 
say of such poisons as alcohol, opium, haschish, tobacco, etc., 



244 ANATOMY, PHYSIOLOGY AND HYGIENE. 

which act so directly and powerfully upon the nervous sys- 
tem ? The same poison does not equally affect all the nerve- 
centres ; thus, strychnine acts upon the spinal centres, but 
not the cerebral ; haschish, upon the sensory centres, giving 
rise to hallucinations ; alcohol, upon the cerebral centres par- 
ticularly. The alcoholic poison first produces an increased 
activity of the muscles, then alternate exaltation and de- 
pression, both physical and mental ; finally, stupor, relaxa- 
tion of the muscles and deep sleep. These symptoms are 
transitory ; but let the poisoning process be continued, and 
true delirium, so well known as " delirium tremens/' follows, 
and at length what is known as " chronic alcoholism ;" and 
while intoxication lasts a few hours, and delirium tremens a 
few days or weeks, chronic alcoholism spreads its baneful in- 
fluence over years, unless death prevents the full develop- 
ment of the tragedy. The victim of alcoholic poisoning is 
equally enfeebled in body and mind. The nervous system 
becomes exhausted, the moral sentiments perverted, the will- 
power broken, and he seems powerless to cease from the fatal 
habit which has produced the change. 

504. With the opium-eater the diseases of the nervous sys- 
tem declare themselves even more rapidly than with the 
drunkard. Says M. Morel : "Given the period at which a 
person begins to smoke opium, and it is easy to predicate the 
time of his death; his days are numbered. " 

505. Tobacco is one of the most virulent poisons. It soothes 
the nerves temporarily, only to leave them more enfeebled 
and irritable. 

Even excessive use of tea and coffee may prove disastrous 
to the health of the nervous system. 

506. The nervous system may be impaired by want of physical 
exercise. Among other agencies that affect the nervous sys- 
tem, none exert a wider influence than bodily exercise. It 
seems to be required to complete the change which the blood 
undergoes while passing through the lungs and skin, without 
which the waste of nerve-element could not be repaired. In 
persons who are merely sedentary, having little occasion for 



nervous system. 245 

active thought, this want of exercise is sufficiently mis- 
chievous ; but when there is great mental activity, the mis- 
chief is vastly increased. Thousands of ministers, lawyers, 
those who sit in the bank and counting-room, shorten their 
days because of this neglect ; especially is this the case in 
America. The English nobility, notwithstanding their many 
indulgences, are a long-lived race, and this is doubtless owing 
to their spending so much time in open-air exercise (208). 

, 507. The nervous system may become impaired by taking too 
little sleep. " Sleep knits up the raveled structure" of nervous 
element; for during sleep, organic assimilation is restoring 
what has been expended in functional energy. A periodical 
renewal of nervous energy as often as once a day is an insti- 
tution of Nature. Among the wise arrangements of the 
Creator, none harmonizes with the wants of the system more 
perfectly than the alternation of day and night. The amount 
of sleep necessary depends upon the age, health, natural 
temperament and occupation of the individual. The more 
rapid the exhaustion of nervous energy from any cause, the 
more sleep will be required. The young and the aged need 
more sleep than the person of middle life; the sick, more 
than the well ; those engaged in mental pursuits, more than 
those wearied by manual labor ; persons of great sensibility, 
more than the sluggish natures whose normal condition is 
more nearly allied to sleep ; woman, more than man. We 
may say in general that the time should not be less than 
from six to eight hours, and most persons require a longer 
period. The time, however, must be proportioned to the 
need, 

Among the more affluent classes, the customs of the times 
are quite incompatible with those habits of sleep which are 
essential to mental vigor. Where amusements are pursued 
till late hours, night after night, the nervous system greatly 
suffers, and every department of the mind becomes un- 
healthy. The man who, eager to become rich, takes time 
from his sleep for business purposes, draws from his brain 
capital. The mother — alas ! here we must stop. Mothers 

21* 



246 ANATOMY, PHYSIOLOGY AND HYGIENE. 

are the one class who hardly get any rest till the " blessed 
Father takes them in his arms and gives his beloved sleep." 

508. 3d, Harmonious Action of the Various Men- 
tal Powers. That the bodily organs may be directly 
affected by impressions purely mental does not admit of 
doubt. Of this fact the skillful physician never loses sight ; 
for a hopeful, healthful influence of the mind may be made 
a remedial agency quite as powerful as that of drugs and 
plasters. 

509. Regular and systematic mental exercise is essential to 
the health of nerve-tissue. Exercise increases the flow of blood 
to the active part. We have seen this to be the case in the 
muscle, and that by use it is both enlarged and strengthened. 
In like manner the nerve-tissue needs exercise; and as the 
gymnast becomes expert, not by spasmodic muscular efforts, 
but by accurate, persistent drill, so must the mental athlete 
gain his power by the regular performance of such exercise 
as he is able to bear. The gymnast at first feels pain in his 
muscles, but he has only to persevere, with proper intervals 
of rest, and what was at first so difficult becomes easy, while 
power is gained for severer feats. So the person unaccus- 
tomed to mental gymnastics feels headache and confusion at 
first, but frequent repetition will make easy and natural the 
very thoughts which struggled so painfully into existence, 
and the nerve-tissue will gain the firmness which increases 
its capability of action. Under such a course of training, 
the change in the brain-tissue is often so great as to modify 
perceptibly the form of the head. 

510. Says Dr. Kay : " I have no hesitation in saying that, 
of all the means for preserving health, there is nothing more 
sure, or better suited to a greater variety of persons, than 
habits of regular and systematic mental occupation of some 
dignity and worth. In this proposition I would embrace 
all those kinds of employment which pass under the general 
name of business, and which, little as we are disposed to 
recognize the fact, bear the same relation to the health of 
the mind that food, exercise, etc., do to the health of the 



NERVOUS SYSTEM. 247 

body. Work is the condition of our being as active and 
progressive creatures." 

Employment which is steadily pursued as a part of the 
established routine of life, and felt to be, in some degree, 
a matter of necessity, has an effect on the mind far more 
salutary than that which depends on the impulse of the mo- 
ment, and is determined by no sense of necessity, no force 
of habit. 

511. The saddest effects of the absence of stated useful em- 
ployment are seen among women of easy circumstances. "It 
is a poor view of woman's duties and capacities that confines 
her to a little busy idleness, because the chances of fortune 
have placed her beyond the necessity of earning a living; 
and they must have but a narrow view of the exigencies of 
social life who believe that any woman of tolerable health 
and strength may not find abundant opportunities of that 
kind of work which affords no other recompense than the 
consciousness of doing good, and therefore to be done, if done 
at all, by those who can dispense with every other compen- 
sation. A life of idleness and luxurious ease can be no more 
honorable to one sex than to the other, and we know very 
well that in a man it creates no claims upon the respect and 
confidence of the community." 

The little accomplishments of needlework, so generally 
diffused, cannot be dignified with the name of work. Many 
a mind, liberally endowed, from want of mental exertion 
becomes dwarfed, or may end in mental depression, particu- 
larly if ill health or deep affliction throws its weight into the 
scale. 

512. The amount of exercise should be adapted to the health 
and age of the individual. If from any cause the nervous 
system be weakened, an amount of exercise which would be 
quite harmless to one in health may prove disastrous. The 
nerve-tissue of children and youth needs the same care as has 
been shown requisite for other tissues, and overwork, that in 
the adult is followed by fatigue, easily removed by rest, in 
the child may result in irreparable injury. At this period, 



248 ANATOMY, PHYSIOLOGY AND HYGIENE. 

the tissue is soft and yielding, and when the blood-vessels 
become long distended by great activity, they may become 
permanently enlarged, and permanent congestion produced. 

Parents and teachers should not fail to remember that 
there are important differences in the quality of different 
brains. In some children the mental reaction to impressions 
is sluggish and incomplete ; in others, the reaction, though 
slow, is quite complete ; in others, again, the reaction is 
rapid and lively, but evanescent, so that, though quick at 
perception, they retain ideas with difficulty ; while in others 
there is that just equilibrium between the internal and external 
in which the reaction is exactly adequate to the impression. 
These differences should be taken into the account, and the 
dull intellect roused, while that unduly active should be re- 
strained. It is too often the case, however, that exactly the 
opposite course is pursued. The fond parents and ambitious 
teachers, misled by the early promise of genius, excite the 
child to new activity by unceasing cultivation and the 
never-failing stimulus of praise. For a time the progress of 
the child is all they could desire, but in exact proportion as 
the picture of the future brightens to their fancy, the proba- 
bility of its realization lessens. The brain, worn out by pre- 
mature exertion, loses its tone, leaving the mental powers 
weakened and depressed for the remainder of life. The ex- 
pected prodigy is then outstripped by many whose dull out- 
set promised him an easy victory. 

513. We often hear the saying, " The valedictorian is 
never heard of after Commencement-day ;" and it is too 
often true when the honors are gained at an early age. The 
present tendency is to treat the mind like a race-horse, goad- 
ing it on to make a certain round in a given time, and that 
before the brain-tissue has gained the consolidation requisite 
for severe exertion. Mary Lyon, with her characteristic 
wisdom, refused to admit to the Mount Holyoke course of 
study girls under sixteen years of age, and from her long list 
of applicants usually selected those not less than eighteen. 

Let the material organ of the mind be subjected to a 



NERVOUS SYSTEM. 249 

systematic, thorough, gymnastic training, taking for it the 
necessary time, and the firm, educated tissue will be fitted for 
enduring labor in later years ; but let it be weakened in 
youth, and it must ever work under a burden, if indeed it 
work at all. 

Moderation in mental exertion is also a necessity with the 
aged, as they have no vitality for recuperation after severe 
exhaustion. 

' 514. Intense activity too long continued impairs the strongest 
brain. The nerve-cells in a state of rest are neutral in their 
chemical character, but after severe exercise they become 
acid. When in this condition it is hazardous to continue the 
exercise. Sufficient rest should be taken to restore them to 
their normal condition. Congestion, or an undue accumula- 
tion of blood, also attends excessive functional action. The 
effect of severe congestion in the spinal centres is to produce 
convulsions ; in the sensory centres, roaring in the ears, 
flashes of light before the eyes and various hallucinations ; 
in the ideational centres, stagnation of ideas, swimming in 
the head, and, if long continued, irregular and convulsive 
action of the cells, causing delirium. The co-ordination of 
function is destroyed, the will-power abolished. The de- 
lirious ideas are the expression of a condition of things in 
the supreme centres analogous to that which in the spinal 
cord utters itself in convulsions. 

515. The required rest is often afforded by recreation and 
amusement " Important as stated employment unquestion- 
ably is to the mental health, amusement or recreation is 
scarcely less so. Few persons, whatever their mental charac- 
ter or temperament, can safely dispense with these altogether. 
Even the most commanding intellects sometimes seek the 
recreation which their exhausting labors make necessary in 
forms of amusement which, to those who feel the necessity 
less, seem to be frivolous and puerile. Endowed as we are with 
the faculty of being amused, it seems to be a reflection on the 
Author of our being to regard amusements as something to 
be carefully shunned rather than sought and enjoyed. 

L* 



250 ANATOMY, PHYSIOLOGY AND HYGIENE. 

"To those whose life is one of severe toil and harassing 
care, amusements constitute almost the only practicable 
means for repairing the constant waste of the nervous 
energy. Especially is this want felt by women in the 
humbler walks of life, whose daily round of care and toil 
not only draws more largely than that of the stronger sex on 
the physical and mental energies, but is lightened by none 
of that relief which is afforded by a greater variety of duties 
and more frequent periods of rest." 

Observation, — The brain, when severely taxed, is often 
rested by some kind of mental exercise which, without being 
fatiguing, requires just enough effort to impart interest. 
Hence, a change from Mathematics to the Languages, or 
from these to music, poetry or painting, will give the needed 
relaxation. 

516. To maintain the highest mental vigor, each faculty 
of the mind should receive its due share of cultivation. Our 
various faculties were not bestowed at random, to be used or 
not as inclination may prompt, but each has its appointed 
place in the mental economy. Each bears some relation to 
every other, making one harmonious whole. All cannot and 
need not receive the same amount of cultivation ; but let any 
one power be so neglected that it might as well be wanting, 
or let it be applied to some other than its destined use, and 
an element of strength is lost, the mind becomes to a greater 
or less extent weakened and one-sided, and therefore jars in 
its working. One must form habits of attention, accustom 
the mind to continuous thought, cultivate the reasoning 
powers and beget a taste for exact knowledge, if he would be 
in any measure equal to the intellectual effort essential to 
true success in every calling of life. He must, however, also 
call into action the creative power of the mind, the imagina- 
tion, to give vividness to his conception, to add force to his 
reasoning and to light up the whole horizon of his thought. 
Many cry out against this faculty, forgetting that it is God- 
given, and capable of a culture that shall make it of inesti- 
mable value. It is the abuse of it, not the use, which we are 



NERVOUS SYSTEM. 251 

to guard against. Its exercise must not be indulged to an 
extent incompatible with the claims of the other faculties. 
It must not be allowed to fashion with unbridled power our 
principles and motives, our aims and ends. Give it, however, 
the purest material to work with, and, within proper bounds, 
no faculty is of more real service or more worthy of our re- 
gaFd. Especially is it of value in presenting to the mind an 
ideal of excellence, a standard of attainment, practicable and 
desirable, but loftier than anything we have yet reached. 

517. The cesthetie faculty, the love of the beautiful, should 
not be allowed to remain inactive. Its importance is recog- 
nized only as we understand its value. An object is beautiful 
to us just in proportion to our power to discover through the 
material form the thought of which this form is but the ex- 
pression ; for beauty is but the spirit looking out through 
the visible, the material. Is not he, then, a happier, a wiser 
and a better man, who so develops this faculty that he may 
not only read the thought and sentiment embodied in the 
works of art, but also the thoughts of the Creator in their 
varied forms of expression through all the kingdoms of 
Nature ? 

518. Man has also a moral faculty, the power of discrimi- 
nating between right and wrong, which is quickly followed 
by the feeling of obligation to do the right and avoid the 
wrong. Upon the right use of these faculties depend the 
happiness and the destin) r of man. The power of an ap- 
proving conscience over the human mind, and consequently 
over the health of the Nervous System, cannot be over-esti- 
mated, while on the other hand, the torments of an accusing 
conscience not only "cut the sinews of the soul's inherent 
strength," but snap one by one the gossamer-filaments of the 
brittle thread of life. 

We have given only a glance at a few of the mental facul- 
ties, but should we take them one by one, through all the 
departments of mind, and note their uses, we should find 
none which could be unused or misused without detriment to 
our health, happiness or usefulness. 



252 ANATOMY, PHYSIOLOGY AND HYGIENE. 

519. Concerning the hygienic influence of a Harmonious 
Development of the Mental Powers, Dr. Ray says: 
" A partial cultivation of the mental faculties is incompatible 
not only with the highest order of thought, but with the highest 
degree of health and efficiency. The result of professional 
experience fairly warrants the statement that in persons of a 
high grade of intellectual endowment and cultivation, other 
things being equal, the force of moral shocks is more easily 
broken, tedious and harassing exercise of particular powers 
more safely borne, than in those of an opposite description, and 
disease, when it comes, is more readily controlled and cured. 
The kind of management which consists in awakening a new 
order of emotion, in exciting new trains of thought, in turn- 
ing attention to some new matter of study or speculation, 
must be far less efficacious, because less applicable, in one 
whose mind has always had a limited range than in one of 
larger resources and capacities. In endeavoring to restore 
the disordered mind of the clodhopper who has scarcely an 
idea beyond that of his manual employment, the great diffi- 
culty is to find some available point from which conservative 
influences may be projected. He dislikes reading, he never 
learned amusements, he feels no interest in the affairs of the 
world ; and unless the circumstances allow of some kind of 
bodily labor, his mind must remain in a state of solitary 
isolation, brooding over its morbid fancies, and utterly in- 
competent to initiate any recuperative movement." 

§ 48. Comparative Neurology. — The Comparison of the Nervous 
System of other Mammals with that of Man — Of Birds — Of Reptiles — 
Of Fishes. The Arrangement of the Nervous System of Mollusks — 
Of Hadiata, 

520. We have seen that in the Motory and Nutritive ap- 
paratuses, there is an arrangement and condition of tissues, 
organs and functions, in all classes of vertebrates, homologous 
to those in man. Analogy would induce the supposition, that 
in the arrangements and appointments of the nervous system 
a similar condition would be found. Here are found gang- 



NERVOUS SYSTEM. 



253 



lia, commissures, and nerves afferent and efferent, but the 
highest development, the convoluted hemispherical ganglion, 
seems to be wanting in the lower orders of the mammalia, in 
birds, reptiles and fishes; with this general exception, all 
other homologous parts are more or less developed. 

Fig. 164. 




Fig. 165. 




Fig. 164 {Owen). Base of Brain of a Horse. — 1, Cerebrum. 2, Optic ganglion. 3, 
Cerebellum. 4, Medulla Oblongata and Spinal Cord. 

Fig. 165. Brain of a Bird. — 1, Cerebrum. 2, Optic ganglion. 3, Cerebellum. 4, 
Medulla Oblongata. 

521. In the Mammalia, the relative size of the cerebrum 
and cerebellum, except in the lowest order (monotremata), 
as the ornithorynchus, is about the same as in man, but in 
birds the cerebellum is proportionately larger than the cere- 
brum ; the sulci of the cerebrum and cerebellum of other 
mammals and birds are less developed than in man, and the 
same is true of the relative size of the brain, large and small, 
also certain ganglia are comparatively larger. In the horse, 

22 



254 ANATOMY, PHYSIOLOGY AND HYGIENE. 

ox, etc., the olfactory, optic and auditory ganglia are large, 
and the senses of smell, sight and hearing are acute. This is 
particularly apparent in birds, as the eagle, vulture and buz- 
zard. In these, vision is not only far-reaching, but acute, and 
the same is true, to a certain extent, of smell and hearing. 
In some animals, as the mole, where vision is feeble, and in 
others where smell or hearing is obtuse, the ganglionic bulbs 
are very small and the nerves very delicate. 

522. In Birds the hemispheres are not united by a corpus 
callosum, as in mammals; the cerebellum is proportionately 
larger than the medulla oblongata ; and the comparative 
weight of the brain to the body is less than in mammals. 



Fig. 167. 





Fig. 166. Brain of an Alligator.— 1, Olfactory ganglia. 2, Cerebrum. 3, Optic 
ganglia. 4, Cerebellum. 5, Medulla Oblongata and Spinal Cord. 

Fig. 167. Brain of a Fish.— 1. Olfactory ganglia. 2, Cerebrum. 3, Optic ganglia. 4, 
Cerebellum. 5, Medulla Oblongata and Spinal Cord. 

523. The brain of Reptiles constitutes but a very small part 
of the body. It is smooth, and without convolutions. The 
hemispheres are hollow, and there is no striated body. The 
cerebellum sends no prolongations across the medulla ob- 
longata, so as to form a kind of ring, as in mammals. 

524. The relative size of the cerebrum in man, compared 
with that of the mammals, birds, reptiles and fishes, varies 
much. In some few, the relative weight between the brain 



NERVOUS SYSTEM. 255 

and body is about the same as in man, while in others it 
is less — seemingly an homologous appendage, as in the orni- 
thorynchus. As we descend in the scale of animal life, 
the cerebellum, the medulla oblongata and the ganglia of 
some of the special senses, as of smell and vision, are larger 
relatively than in the corresponding parts in man, since these 
animals depend upon them for their subsistence and safety. 

525. The spinal cord of all mammals, birds, reptiles and 
fishes varies most in length, but in structure, investment and 
function it resembles that of man. The number of pairs of 
spinal nerves correspond to the number of the vertebra?, but 
the size of the cord is relatively larger than the cerebrum, 
also the cerebellum and several of the ganglia. 

526. The brain of the Fish is small ; it does not fill the 
whole cranial cavity, there being found within it a spongy, 
fatty mass. The investment and protection of some of the 
organs of special sense are modified, as seen in the eye of some 
fishes, the deep-sea shark for instance, where the sclerotic 
tunic of the eye is bony, in order to protect this organ from 
the great pressure of the water. Perhaps the most wonderful 
arrangement is found in the electric fishes, as the common 
Torpedo, Malapterurus, and the Electric Eel of South 
America. 

527. "The torpedo is a cartilaginous fish. Fig. ir>8. 
Its body is smooth, and represents a disc 
nearly circular, the anterior edge of which is 
formed by two prolongations of the muzzle, 
which on each side proceed to unite with the 
pectoral fins, and leave between these organs 
the head and the branchiae, an oval space, in 
which is lodged the electric apparatus of the 
fish. This apparatus is composed of a num- 
ber of vertical membranous tubes, closely 
packed like honeycomb, and subdivided by torpedo. 
horizontal partitions filled with mucosites, 

and animated by several very large branches of the pneumo- 
gastric nerve, which, in this and other electric fishes, is larger 




256 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



than the spinal cord. In these singular organs is produced 
the electricity which has now been proved to resemble in 
every respect common electricity. By experiment it has 
been ascertained that this property depends on the posterior 
lobe of the brain, and that by destroying this lobe, or cutting 
the nerves proceeding from it, the faculty is lost." 

528. "The Gym- 
notus, or Electric 
Eel, possesses the 
power in the highest 
degree. It is met 
with in vast numbers 
in the rivulets and 
stagnant waters of 
the immense plains 
of South America. 
The electric shocks, 
which it discharges 
at will, are sufficient- 
ly strong to kill men 
and horses, and be- 
ing transmissible 
through water, the 
gymnotus does not 
require to touch its 
prey. At first the 
electric discharges 
are feeble, but when 
roused they become 
terrible ; but by this 
effort it becomes ex- 
hausted, and requires 
repose before it can 
renew the attack : this is the moment its captors avail them- 
selves of to seize it. The electric organs are arranged along 
the back and tail." 

In the Articulata, the body is different in its general 




Fig. 169. Electric Organs of Torpedo. — 1 
2, Spinal cord. 3, Eye and optic nerve. 4, 



Brain. 
Spinal 



nerve. 5, Branchia?. 6, Electrical organ 
gastric nerve. 



. Pneumo- 



NEKVOTJS SYSTEM. 



257 



structure and the nervous system is 
correspondingly modified. The body 
is composed of several sections artic- 
ulated with each other in a lineal 
series. The ganglia of the nerves 
of special sensation, as of sight and 
hearing, of motion, of respiration 
and nutrition, are larger than those 
of general sensation. 

In the nervous system of the cen- 
tipede, whose general structure is 
similar to that of other articulates, 
the ganglia are arranged in pairs 
of nearly equal size, except the 
ganglion that answers to the brain, 
which is larger, along the ventral 
surface of the alimentary canal. 

Fig. 171. 



Fig. 170. 




Fig. 170. Nervous System of 
an Insect. — 1, 1, Central gang- 
lia. 2, 2, 2, Nerves that connect 
the ganglia. 

Each pair is connected 




Fig. 171. Diagram of a Centipede. 

with the preceding, with the integument or skin and with the 
muscles of its own segment, by sensitive and motor filaments 
of nerves. 

529. In Mollushs are found the ganglia and commissure 
arrangement, with nerves sensitive and motor, afferent and 
efferent, and on a plan corresponding to the body. The 
structure of the organs of sense is less complete than in 
vertebrate animals. Some mollusks are gifted only with the 
sense of touch and taste ; a great number have eyes, whose 
structure varies ; none have yet been found possessing a spe- 
cial organ for smell. 

530. In the Radiata, the star-fish manifests one of the 

22* 



258 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



simplest forms of the nervous system. It consists of a central 
mass, with five arms radiating from it. In the centre is the 
mouth, and beneath it the stomach or gastric cavity, which 
sends prolongations to each limb. The nervous system con- 
sists of five similar ganglia situated in the central portion at 
the base of the arms. These ganglia are connected by com- 
missures, and each sends off nerve-filaments to the cor- 
responding limbs. 



Fig. 172. 



Fig. 173. 





Fig. 172. Diagram of the Type of a Mollusk. — 1, (Esophagal ganglia. 2, Cerebral 

3, Pedal or locomotive ganglia. 4, Respiratory ganglia. 
Fig. 173. Diagram of a Radiata — The Star-Fish. 



531. We have seen that in all grades of the animal king- 
dom the cell-structure obtains, but in the lowest forms of 
animal life nerve does not exist. The stimulus which the 
little creature receives from without would seem to produce 
some change in the molecular relations of its almost homo- 
geneous substance, and these insensible movements col- 
lectively to amount to the sensible movement which it 
makes ; the molecular process in such case being perhaps 
not unlike that which ensues and issues in the coagulation 
of the blood when the fibrin is brought in contact, as some 
think, with a foreign substance. The perception of the 



NEBVOUS SYSTEM. 259 

stimulus by the creature is the molecular change which en- 
sues, the imperceptible motion passing, by reason of the 
homogeneity of its substance, with the greatest ease, from 
element to element of the same hind, as it were by an infec- 
tion, or as happens in the folding of the leaves of the mimosa, 
or sensitive plant ; and the sum of the molecular motions, as 
necessarily determined in direction by the form of the ani- 
mal, results in the visible movement. 

, " With the differentiation of tissue and increasing com- 
plexity of organization which are met with as we ascend in 
the animal kingdom, the nervous tissue appears, but at first 
under a very simple form. Its simplest type may be repre- 
sented as two fibres that are connected by a nerve-cell ; the 
fibres are apparently simple conductors, and might be aptly 
compared to the conducting wires of a telegraph, w 7 hile the 
cell, being the centre in which nerve-force is generated, may 
be compared to the telegraphic apparatus; in it the effect 
which the stimulus of the afferent nerve excites is transmitted 
along the efferent nerve, and therein is displayed the simplest 
form of that reflex action which plays so large a part in ani- 
mal life." 

The relations of the animal kingdom afford a striking evi- 
dence of divine unity, bound together in the closest harmony, 
and the work of Him who was the Beginning and will be 
the End. 



CHAPTER XII. 

THE ORGANS OF SPECIAL SENSE. 

Under this head are classed the Tongue, the Nose, the Eye, 
the Ear and the Tactile portions of the Nervous System. 

\ 49. The Anatomy of the Organs of Special Sense. — The 

Organ of Taste — Of Smell. The Coats of the Eye. The Humors of 
the Eye. The Muscles of the Eye. The Protecting Organs. Classi- 
fication of the Organs of Hearing. The External Ear . The Labyrinth. 
The Internal Ear. The Organs of Touch. Two Layers of Skin. The 
Epidermis. The Dermis. The Hairs. The Sebaceous Glands. The 
Perspiratory Glands. The Nails. 

532. The organ of the Sense of Taste is the mucous 
membrane which covers the Tongue, especially the back part 
of this organ, and the palate. Upon the upper surface of the 
tongue the mucous membrane has various little eminences, 
called papillce, resembling the villi of the intestines. The 

Fig. 174. 



Fig. 174 {Leidy). Diagram of the Papilla of the Tongue, moderately magnified. 
1, Capitate papillae. 2, Conical papillae. 3, Epithelium. 4, The same structure form- 
ing bunches of hair-like processes. 5, Connective tissue. 

principal of these are of a composite character, and present 
three varieties — the Oircumvallate, the Fungiform and the 
Conical. The Oircumvallate papillae are shaped like the 
letter V with the point turned downward, and are surrounded 

260 



THE ORGANS OF SPECIAL SENSE. 



261 



by an annular wall-like elevation, whence their name. They 
are about a dozen in number, and are found upon the pos- 
terior part of the tongue. The Fungiform papillae are broad 
at the free extremity and narrow at the base, having some- 
thing of the mushroom shape, whence their name. They are 
more numerous than the circumvallate, and are scattered 
over the surface of the tongue, but are especially numerous 
at and near the tip. The Conical papillae are smaller and 
more numerous than the others, and are found in the inter- 
vals between them, arranged in rows diverging from the 
median line of the tongue. All the above-described papillae 
and the spaces between are covered with simple papillae, 
conical in form. From those surrounding the conical papillae, 
the squamose epithelium rises in hair-like appendages, which 
give a brush-like arrangement, admirably adapted, to the im- 
bibition of liquids to be tasted. These hair-like appendages 
give the velvety character to the surface of the tongue, and 
upon them the furred condition of this organ depends. 
Minute blood-vessels and nerves pass up into these papillae, 
thus giving a large extent of sensitive surface. 




Fig. 175 (Daltori). Diagram of the Tongue, with its sensitive nerves and papillae. 
1, Lingual branch of fifth pair. 2, Glossopharyngeal nerve. 



Nervous filaments are received from the fifth, ninth and 
twelfth pairs of nerves. The branch of the fifth, called the 
Gust'a-to-ry, is the nerve of taste and ordinary sensibility ; 



262 ANATOMY, PHYSIOLOGY AND HYGIENE. 

the twelfth, called the Hypo-glossal, of voluntary motion. 
By means of the ninth, or Glossopharyngeal, the tongue is 
brought into association with the fauces, oesophagus and 
larynx. It is of obvious importance that these parts should 
act in concert; and this is effected by the distribution of 
this nerve. 

Fig. 176. 




Fig. 176. The Distribution of the Fifth Pair of Nerves. — 1, The orbit for the eye. 
2, The upper jaw. 3, The tongue. 4, The lower jaw. 5, The fifth pair of nerves. 6, The 
first branch of this nerve, that passes to the eye. 9, 10, 11, 12, 13, 14, Divisions of this 
branch. 7, The second branch of the fifth pair of nerves is distributed to the teeth of 
the upper jaw. 15, 16, 17, 18, 19, 20, Divisions of this branch. 8, The third branch of 
the fifth pair, that passes to the tongue and teeth of the lower jaw. 23, The division 
of this branch that passes to the tongue, called the gustatory. 24, The division that 
is distributed to the teeth of the lower jaw. 



533. The organ of the Sense of Smell is a part of the 
delicate mucous membrane lining the nasal passages. These 
passages extend from the opening of the nostrils in front, to 
the pharynx behind; they are high, vaulted and narrow, 
and separated from each other by a partition partly bony, 
and partly cartilaginous. This double cavity is separated 



THE ORGANS OF SPECIAL SENSE. 



263 



from the mouth by a bony floor (the hard palate), which is 
continued backward to the root of the tongue by a fleshy 
curtain, called the soft palate. In ordinary positions of the 
mouth, this palate and the root of the tongue effect a closure 
between the mouth and the pharynx. Each of the outer 
walls of the nasal chamber has three bony processes called tur- 
binated bones, arranged one above another, like shelves. The 
front of the chamber is bounded by a thin plate of bone, filled 
with perforations, hence, named the cribiform, or sieve-like 

Fig. 177. 




Fig. 177. A Vertical Section of the Middle Part of the Nasal Cavities. — 7, The 
middle spongy bones. 8, The superior part of the nasal cavities. 10, The inferior 
spongy bones. 11, The vomer. 12, The upper jaw. 13, The middle channel of the 
nose. 14, The lower channel of the nose. 17, The palatine process of the upper jaw- 
bone. 18, The roof of the mouth covered by mucous membrane. 19, A section of this 
membrane. 



plate. Upon it, rest the olfactory lobes which send numerous 
filaments through the perforations to the mucous membrane 
of the two upper turbinated bones, affording the special sense 
of smell ; the membrane of the lower bone receives a branch 
from the fifth nerve, which is endowed with common sensi- 
bility only ; the odor of cologne, for example, is distinguished 
by the olfactory nerve, and the pungency, by the branch of 
the fifth nerve. 



264 



ANATOMY, PHYSIOLOGY AND HYGIENE. 




Fig. 178. A Side View of the Passage of the Nostrils, and the Distribution of 
the Olfactory Nerve. — £, The olfactory nerve. 5, The fine divisions of this nerve on 
the membrane of the nose. 6, A branch of the fifth pair of nerves. 

534. The chief organ of the Sense of Sight is the Eye. 
The globe of the eye, or eyeball, is composed of three con- 
centric envelopes — viz., the Sclerotica, with the Cornea in 
front ; the Cho'roidea, with the Iris in front ; and the Retina, 
which is internal. These make up most of the solid part of the 
eyeball, which is a hollow sphere filled with three fluid or semi- 
fluid substances — the Aqueous Humor, the Crystalline Lens and 

the Vitreous Humor. 

Fig. 179. 




Fig. 179. A Section of the Globe of the Eye. — 1, The sclerotic coat. 2. The cornea. 
(This connects with the sclerotic coat by a bevelled edge.) 3, The choroid coat. 6, 6, 
The iris. 7, The pupil. 8, The retina. 10, 11, 11, Chambers of the eye that contain the 
aqueous humor. 12, The crystalline lens. 13, The vitreous humor. 15, The optic 
nerve. 16, The central artery of the eye. 



THE ORGANS OF SPECIAL SENSE. 265 

The Sclerotica, or Sclerotic coat, invests the globe of 
the eye, excepting the part covered with the cornea in front. 
It is composed of white fibrous tissue arranged in many 
layers, which cross each other at right angles, and form a 
tunic of great strength. It is white, glassy and opaque, and 
is commonly called " the white of the eye." It has few 
blood-vessels and seems destitute of nerves. 

The Choroidea, or Second Coat of the eye, has some 
fibrous tissue like the sclerotica, but is chiefly composed of 
blood-vessels and pigment-cells. These cells give the coat an 
intense black color on the inside, but externally it is brown. 
It lines the sclerotica, and is connected with it by a delicate 
areolar tissue. It is perforated behind, for the passage of the 
optic nerve, and terminates in front in the cil'iary ligament 
(composed chiefly of dense areolar tissue), in the anterior 
part of which the iris is inserted. This muscle also lies at the 
juncture of the sclerotica and cornea, being in connection 
with the first coat and cornea, and the second coat and iris. 

The Ciliary Processes consist of a number of minute, 
triangular folds, formed apparently by the plaiting of the 
internal layer of the choroid coat toward its front part. 
Their bases are toward the pupil, and the free portion rests 
against the circumference of the crystalline lens. These 
processes are covered with pigment-cells. 

The Iris occupies the opening of the choroidea in front, 
forms a partition between the anterior and the posterior 
chambers of the eye, and is pierced by a circular opening, 
which is called the Pupil. It is free, except at its peripheal 
attachments, and floats freely in the aqueous humor. The 
posterior surface' of the iris, or uvea, is thickly covered with 
pigment ; but the anterior surface gives the color of the eye, 
so remarkably and beautifully varied in different individuals, 
and presenting numerous blended tints of black, brown, blue 
and gray. The iris is generally regarded as a modification 
of muscular tissue. It has two layers of fibres — one layer of 
radiating fibres, converging from the circumference to the 
centre, the other of circular fibres. 
23 M 



266 

The Retina is the inner coat of the eye, formed by the 
expansion of the optic nerve upon the inner side of the cho- 
roid coat, but not extending so far forward. It ends at a 
short distance from the ciliary ligament, in a jagged edge, 
from which an exceedingly fine membrane extends to the 
ciliary processes. Its inner surface is bounded by an exceed- 
ingly delicate membrane, called the " membrana limitans," 
which separates it from the vitreous humor. 




Fig. 180. A View of the Anterior Segment of a Transverse Section of the Globe 
of the Eye, seen from within. 1, The divided edge of the three coats— sclerotica, cho- 
roidea and retina. 2, The pupil. 3, The iris : the surface presented to view in this sec- 
tion being the uvea. 4, The ciliary processes. 5, The scalloped anterior border of the 
retina. 

535. Of the three humors, or liquid substances of the eye, 
the Aqueous, or watery, is situated in the anterior portion 
of the organ behind the cornea. It is an albuminous fluid, 
with an alkaline reaction and liquid like water. The iris is 
placed vertically in the fluid, the space between it and the 
cornea being the anterior chamber of the eye, and that be- 
tween the iris and crystalline lens behind, the posterior cham- 
ber. The two chambers are lined by a membrane secreting 
the aqueous humor. 

The Crystalline humor, or lens, is situated immediately 
behind the pupil, and is surrounded by the ciliary processes. 
It is invested by a transparent, elastic membrane, called the 



THE ORGANS OF SPECIAL SENSE. 



267 



capsule of the lens. The humor is more convex on the pos- 
terior than on the anterior surface. It is imbedded in the 
anterior part of the vitreous humor, from which it is separated 
by a thin membrane. The lens consist of thin layers, like 
the coats of an onion. The external layer is soft, but each 
successive one increases in firmness. 

Qbservation. — When the crystalline lens or its investing 
membrane is changed in structure, preventing the rays of light 
from passing to the retina, the affection is called a cataract 

Fig. 181. 




Fig. 181 (Leidy). Muscles of the Eye. — 1, The palpebral elevator muscle. 2, The 
superior oblique. 3, The pulley through which the tendon of insertion plays. 4, Supe- 
rior straight muscle. 5, Inferior straight muscle. 6, External straight muscle. 7, 8, 
Its two points of origin. 9, Interval through which pass the oculo-motor and abducent 
nerves. 10, Inferior oblique muscle. 11, Optic nerve. 12, Cut surface of the malar pro- 
cess of the superior maxillary bone. 13, The nasal orifice. A, The eyeball. 

536. The Vitreous Humor forms the principal bulk of 
the globe of the eye. It is an albuminous fluid resembling 
the aqueous humor, but is more dense, and if once discharged 
by disease or accident, it is irrecoverably lost; while the 
aqueous humor may be lost and afterward restored. This 
humor is enclosed in a delicate membrane, called the hy'a- 
loid, which sends processes into the interior of the globe of 
the eye, forming the cells in which the humor is retained. 



268 ANATOMY, PHYSIOLOGY AND HYGIENE. 

537. The Muscles of the eye are six in number. They 
are attached at one extremity to the orbit behind the eye ; at 
the other extremity they are inserted by broad, thin tendons 
to the sclerotic coat, near the junction of the cornea. The 
white, pearly appearance of the eye is caused by these 
tendons. 

Observation, — If the external muscle is too short, the eye 
is turned out, producing the " wall eye ;" if the internal 
muscle is contracted, the eye is turned inward toward the 
nose, and is called a " cross eye." 

538. The Protecting Organs are the Orbits, Eyebrows, 
Eyelids and Lach'rymal Apparatus. 

The Orbits are deep, bony sockets in which the globes of 
the eye are placed. The bottom of each orbit has a large 
perforation, giving passage to the optic nerve. These cavities 
are lined with a thick cushion of fat. 

The Eyebrow t s, forming the upper part of the boundary 
of the orbits, are two tegumentary prominences covered with 
coarse hair. 

The Eyelids are two movable curtains, having a delicate 
skin on the outside, muscular fibres beneath, and a narrow 
cartilage on their edges, which tends to preserve the shape 
of the lid. Internally, they are lined by a smooth mucous 
membrane, which is reflected on the front of the eye upon 
the sclerotica. This membrane is called the Co7ijuncti'va. 

Observation. — When this membrane is inflamed, it some- 
times deposits a whitish material called lymph, which accounts 
for the films, opacities and white spots seen upon the eye after 
the inflammation has subsided. 

On the internal surface of the cartilage there are found 
several small glands, which have the appearance of parallel 
strings of pearls. They open by minute apertures upon the 
edges of the lids. 

The edges of the eyelids are furnished with a triple row of 
hairs, called eyelashes, which curve upward from the upper 
lid, and downward from the lower. 

The Lachrymal Apparatus which secretes the tears 



THE ORGANS OF SPECIAL SENSE. 



269 



consists of the Lachrymal Gland with its ducts, Lachrymal 
Canals and the Nasal Duct 

The Lachrymal Gland is situated at the outer and upper 
angle of the orbit, occupying a depression in the orbital plate 
of the frontal bone. Ten or twelve small ducts pass from this 
gland and open upon the upper eyelid, where they pour upon 
the conjunctiva the lachrymal fluid, or tears. 

Fig. 182. 




Fig. 182 (Leidy). The Left Eyelid and Lachrymal Gland, turned Forward and 
Inward, to show their Inner Surface. — 1, Upper and lower part of the orbit. 2, 
Portion of the palpebral orbicular muscle. 3, Attachment of this muscle to the inner 
margin of the orbit. 4, Perforation for the passage of the external nasal nerve. 5, Offset 
described as the tensor muscle of the eyelids. 6, Palpebral glands. 7, Posterior, and 8, 
anterior portions of the lachrymal glands. 9, 10, Ducts. 11, Orifices opening on the 
inner surface of the upper eyelid. 12, 13, The lachrymal orifices at the summits of the 
lachrymal papillae. 



The Lachrymal Canals commence at the free borders 
of each eyelid, near the internal angle of the eye, by two 
minute orifices, called "punc'ta lach'rymalia" (tear points). 
Each of these ducts communicates with the sac at the upper 
part of the nasal duct. 

The Nasal Duct is a short canal about three quarters 
of an inch in length, directed downward and backward to 

23*- 



270 ANATOMY, PHYSIOLOGY AND HYGIENE. 

the inferior channel of the nose, where it terminates by an 

expanded orifice. The tears, secreted by the lachrymal 

gland, are conveyed to the eye by the small ducts before 

described. They are then taken up by the puncta lachry- 

malia and carried by the lachrymal canals into the lachrymal 

sac, from which they are passed to the nasal cavities by the 

nasal duct. 

Fig. 183. 




Fig. 183. View of Lachrymal Gland and Nasal Duct. — 1, The lachrymal gland. 2, 
Ducts leading from the lachrymal gland to the upper eyelid. 3, 3, The puncta lachry- 
malia. 4, The nasal sac. 5, The termination of the nasal duct. 

539. The Sense of Hearing does not strictly belong to 
one organ, but to several, which are grouped into three divi- 
sions — the External Ear, the Tym'panum* and the Labyrinth 
or Internal Ear. 

540. The Labyrinth is so called from its remarkable 
and varied configuration. It is divided into three portions — 
the Vestibule, the Semicircular Canals and the Coch'lea. f 

541. The Vestibule is a small and somewhat triangular 
cavity about the size of a grain of wheat. It is placed almost 
vertically in the centre of the labyrinth, and is a kind of 
entrance-chamber or ante-room to the semicircular canals 
behind and the cochlea in front. 

* Gr., tumpanon, a drum. f Gr., kochlos, to twist. 



THE ORGANS OF SPECIAL SENSE. 

Fig. 184. 



271 




Fig. 184. A View of the Labyrinth Laid Open. — 1, 1, Cochlea. 2, 3, Two canals, 
that wind two and a half turns around a hollow axis (5). 7, Central portion of the laby- 
rinth (vestibule). 8, Fenestra rotunda. 9, Feuestra ovalis. 11, 12, 13, 14, 15, 16, 17, 18, 
The semicircular canals. Highly magnified. 

542. The Semicircular Canals are three curved pas- 
sages, describing more than half a circle, and are about the 
twentieth of an inch in diameter. Two of them open into 
the vestibule at both extremities, and the third at one ex- 
tremity. Both the vestibule and the canals contain a trans- 
parent fluid like lymph, and in this fluid, without touching 
the walls of the cavity, floats a membranous labyrinth, cor- 
responding in form to the osseous one, but considerably 
smaller. It is a sheath or bag enlarged at the vestibule, and 
sending out prolongations into the semicircular canals on the 
the one side and the cochlea on the other. It is filled with 
a lymph-like fluid of greater consistency than that in which 
it floats. The auditory nerve is distributed in the walls of 
this membranous labyrinth, and nervous filaments connect it 
with its osseous counterpart. 

543. In front of the vestibule is the Cochlea, so called 
from its resemblance to a snail-shell. It consists of a bony 



272 ANATOMY, PHYSIOLOGY AND HYGIENE. 

canal which winds around a hollow axis nearly three times, 
gradually decreasing in diameter, and thus forming a spiral 
cone. The interior of the canal is divided into two passages 
by a membranous partition, upon which the remaining parts 
of the auditory nerve ramify. The passages are filled with 
lymph, and communicate with each other at the apex of the 
cone and at the apex of the base ; one opens into the vesti- 
bule, the other into the Tympanum (the Fenestra* Rotunda). 

Fig. 185. 




Fig. 185. A View of tiie Auditory Nerve. — 1, Spinal cord. 2, Medulla oblongata. 
3, Lower part of the brain. 4, Auditory nerve. 5, A branch to the semicircular canals. 
6, A branch to the cochlea. 

In the outer part of the bony wall of the vestibule is the 
Fenestra Ovalis, an oval-shaped perforation about one-eighth 
of an inch in length and one-sixteenth in width. This is 
closed by a thin fibrous membrane, which prevents the escape 
of the fluid from the vestibule, and through it the sonorous 
vibrations pass to the vestibule. 

544. The Tympanum, or middle ear, is an irregular bony 
cavity larger than the vestibule and just outside of it. It is 
separated from the external ear by a thin, semi-transparent 
membrane of an oval shape. This is very closely fitted into 
a groove, between the tympanum and the auditory canal. 
The tympanum is often called the Drum of the ear, and very 
appropriately, for the membrane of the tympanum is in con- 
tact with the atmosphere whose sonorous vibrations beat upon 

* Lat., a window. 



THE OBGANS OF SPECIAL SENSE. 



273 



it much like drumsticks upon the head of a drum. There 
are several openings into the tympanum, of which the largest 
is called the Eustachian tube, from the name of the first 
anatomist who described it. It is a trumpet-shaped canal 
somewhat over an inch and a half long, extending from the 
fore part of the tympanum obliquely inward, forward and 
downward to the pharynx. The tube is lined with a ciliated 
epithelium continuous with that of the pharynx and tympa- 
num. In the tympanic cavity are three bones, or ossicles, 
the smallest in the body, weighing only a few grains. From 
their resemblance to the articles, they have been named the 
Mallet, Anvil (attached to this bone is a little tubercle, or 
orbicular bone, which is sometimes regarded as a separate 
ossicle) and Stirrup, The Mallet and Anvil articulate by a 
hinge-joint; the Anvil and Stirrup by a ball-and-socket 
joint. 

Fig. 186. 




Fig. 186. A View of all the Parts of the Ear, — 1, The canal that leads to the in- 
ternal ear. 2, The membrana tympani. 3, 4, 5, The bones of the ear. 7, The central 
part of the labyrinth (vestibule). 8, 9, 10, The semicircular canals. 11, 12, The chan- 
nels of the cochlea. 13, The auditory nerve. 14, The opening from the middle ear, or 
tympanum, to the throat (Eustachian tube). 

M* 



274 ANATOMY, PHYSIOLOGY AND HYGIENE. 

545. The External Ear lies outside the membrane of 
the tympanum. It is composed of the auditory canal and 
the part which projects from the head. The canal, or Ex- 
ternal Mea'tus* Audito'rius, is partly bony and partly car- 
tilaginous, about one inch in length, and narrower in the 
middle than at the extremities. Short, firm hairs are 
stretched across the tube, preventing the ingress of foreign 
bodies. Beneath the thin cuticle are small follicles which 
secrete the Ceru'men, or wax. The part of the external ear 
outside the cavity has numerous prominences and ridges. 

(For Physiology of Hearing, see 565.) 

546. The skin is the principal part of the body concerned 
in the Sense of Touch, but the tongue and lips also possess 
this sense. The skin consists of two layers. The external, 
or superficial layer, destitute of blood-vessels and nerves, is 
called the Ep-i-derm' is"\ (which consists of two layers, different 
in many respects, one being named the Cuticle, the other the 
Soft Epidermis) ; and an internal, or deeper layer, abundantly 
supplied with nerves and highly vascular, called the Dermis, 
Cutis Vera (or true skin). This layer presents two very dif- 
ferent surfaces, of which the external is called the Papillary 
layer, the internal the Co'ri-um. % 

547. The skin covers the whole exterior of the body, and 
at the margins of the apertures is directly continuous with 
the mucous membrane, which last is an integument of greater 
delicacy, but has substantially the same composition — viz., 
a deep fibrous, sanguine, sensitive layer, a basement mem- 
brane, and an epithelium, or superficial, insensible and blood- 
less layer. Thus the whole body, externally and internally, 
has a complete epithelial investment. 

548. The Epidermis holds the same relation to the dermis 
that the epithelium does to the deeper layer of the mucous 
membrane. It varies in thickness, from the thin, delicate 
membrane upon the internal flexions of the joints, to the 

* Lat., meo, to pass, a passage. f Gr., epi, upon, and derma, skin. 
J Gr., chorion, skin. 



THE ORGANS OF SPECIAL SENSE. 



275 



thickened covering of the soles of the feet- This variation 
is perceptible in infants, before exercise can have had any 
influence. 

Fig. 187. 




- ■ : - - " -■- : ■ " ■ 

Fig. 187. A Vertical Section of the Skin. — 1, 1, The lines, or ridges of the cuticle, 
cut perpendicularly. 2, 2, 2, 2, 2, The furrows or wrinkles of the same. 3, The epider- 
mis. 4, 4, 4, Colored layer. 5, 5, Dermis, or cutis vera. 6, 6, 6, 6, 6, Papillae. 7, 7, Small 
furrows between the papillae. 8, 8, 8, 8, Deeper furrows between each couple of the 
papillae. 9, 9, Cells filled with fat. 10, 10, 10, Adipose layer, with numerous fat vesicles. 
11, 11, 11, Cellular fibres of the adipose tissue. 12, Two hairs. 13, A perspiratory gland, 
with its spiral duct. 14, Another perspiratory gland, with a duct less spiral. 15, 15, Oil- 
glands with ducts opening into the sheath of the hair (12). A diagram. 



During life the Epi- 
dermis is constantly 
undergoing loss, throw- 
ing off the superficial 
epidermoid scales, 
which are constantly- 
renewed by fresh cells, 
originating on the sur- 
face of the true skin. 
These gradually 
undergo transformation 
from the spherical to 



Fig. 188. 




Fig. 188 (Leidy). Fragment of Dandruff from 
the Head. — 1, Portion of dandruff, consisting of 
non-nucleated cells. 2, Several fragments,consisting 
of nucleated cells. 3, Isolated cells, some with and 
some without nuclei. 4, A cell more highly mag- 
nified, exhibiting granular contents and a nucleus. 



276 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



Fig. 189. 



the flattened shape, as they approach the surface of the 
cuticle. 

The soft epidermic layer is the seat of the color of the skin. 
The difference between the blonde and brunette, the European 
and the African, lies only in the deep, newly-formed layers 
of the epidermis. In the whitest skin, the cells of the epi- 
dermis always contain a slight amount of the pigmentary 
tint, which disappears from the cells as this soft layer is 
transformed into the cuticle. 

549. The Cuticle is a translucent, horn-like membrane. 
Its deeper surface is continuous with the soft epidermic layer 

from which it is constantly re- 
newed. Its free surface is inces- 
santly wearing away, or shed in 
small flakes, constituting scurf or 
dandruff. 

550. The Dermis, or True 
Skin, is made up of interlacing 
bundles of white areolar tissue, 
mixed with yellow elastic fibres. 
These are so interwoven as to 
constitute a firm, strong and 
flexible web. In the superficial 
part, the web is so close as to re- 
semble felt cloth. In the deepest 
layers the network is loose, and encloses the hair-follicles 
with their sebaceous glands, and small masses of fat. 

In most situations, plain muscular fibres are found mixed 
with the fibrous and elastic tissues ; these are always present 
where hairs exist, to which parts they are often attached ; 
but on the palms and soles, where these are absent, no mus- 
cular fibres are ever seen. 

551. The outer surface of the dermis, as seen when de- 
nuded, is provided with little conical-shaped projections, 
called Papillce (6, fig. 187). These are prolongations of 
the upper compact tissue of the corium into the newly- 
formed layer of the epidermis. The papilla are very 




Fia. 189 {Leidy.) Scurf from the 
Leg. — 1, A fragment of scurf, consist- 
ing of dried, flattened, non-nucleated 
cells or scales. 2, A few cells with a 
nucleus. 3. A cell more highly mag- 
nified, to exhibit its polyhedral form. 



THE ORGANS OF SPECIAL SENSE. 



277 



Fig. 190. 




numerous on the palm of the hand and on the free border 
of the lips. 

552. The cutis vera is abundantly supplied with blood-ves- 
sels, lymphatics and nerves. Its general surface is covered with 
a close capillary network, from 
which looped vessels project 
and enter the papillae. The 
lymphatics also form a close 
network on the surface. The 
nerves pass upward from the 
subcutaneous areolar tissue, 
and form, as they approach 
the surface, minute plexuses, 
from which the nerve-fibres are 
given off. Some of these fibres 
are lost in the compact tissue 
of the dermis ; others end, per- 
haps, in loops ; and many pass 
into certain of the papillae, for 
it is said that some of these do 
not receive nerve-fibres. In the 
papillae these fibres end in loops, 
or, as in the fingers, the sole of 
the foot, and perhaps on the red 
margin of the lips and the point 
of the tongue, they appear to 
terminate in small oval, con- 
densed bodies, called tactile cor- 
puscles, situated in the centre 
of the papillae. In any case, it 
is supposed that the nerve-fibre 
turns back to rejoin some nerve- 
cell in the nervous centres. 

The network of nerves imbedded in the upper porous 
layer of the true skin is derived from nerves which take 
their winding course through the fat, distended openings of 
the corium. 

24 





Fig. 190 (Leidy). Vertical Section of 
the Skin of the Forefinger across 
Two of the Kldges of the Surface; 
highly magnified. 1, Dermis, composed 
of an intertexture of bundles of fibrous 
tissue. 2, Epidermis. 3, Its cuticle. 4, 
Its soft layer. 5, Subcutaneous con- 
nective and adipose tissue. 6, Tactile 
papillae. 7, Sweat glands. 8, Duct. 9, 
Spiral passage from the latter through 
the epidermis. 10, Termination of the 
passage on the summit of ridge. 



278 



ANATOMY, PHYSIOLOGY AND HYGIENE. 



553. The minute depressions from which the hairs of the 
skin emerge are called the Hair-follicles, or sacs. They are 
buried in the corium, or true skin. At the bottom of the 
follicle is a more or less elevated portion of the dermis, often 
forming a distinct papilla, which is destitute of cuticle. The 

root of the hair is composed of 
soft, pale and somewhat com- 
pressed nucleated cells ; it is 
adherent to the lining of the fol- 
licle, or root-sheath. When a 
hair is plucked out, the sheath 
adheres to it, but the vascular 
papilla at the bottom of the fol- 
licle remains, and a new hair is 
generated upon it. If the papilla 
is destroyed, no new hair can be 
formed. All these papillse, ex- 
cept those of the finest hairs, 
probably receive nervous fibrils. 
The part of the hair projecting 
above the surface is called the 
Shaft. The shaft is usually cylin- 
drical, but sometimes flattened. 
It consists of an outer part, called 
the Cortex, composed of a single 
layer of imbricated scales whose 
edges are directed toward the 
point of the hair.- Beneath the 
cortex is the so-called fibrous part 
of the hair, which constitutes its 
bulk, and consists of fusiform 
cells clustered into flattened 
fibres, running longitudinally and 
intermixed with pigment granules. Lastly, the very deepest 
cells, occupying the centre of the shaft and constituting the 
pith, are not elongated, but polyhedral and loosely connected 
together, and containing chiefly pigment or fat granules. 




Fig. 191 {Lidy). Diagram of Struc- 
ture of the Root of a Hair within 1 
its Follicle. — 1, Hair papilla. 2, 
Capillary vessel. 3, Nerve-fibres. 4, 
Fibrous wall of the hair-follicle. 5, 
Basement membrane. 6, Soft epider- 
mic lining of the follicle. 7, Its elastic 
cuticular layer. 8, Cuticle of the hair. 
9, Cortical substance. 10, Medullary 
substance. 11, Bulb of the hair, com- 
posed of soft polyhedral cells. 12, 
Transition of the latter into the corti- 
cal substance, medullary substance 
and cuticle of the hair. 



THE ORGANS OF SPECIAL SENSE. 



279 



Fig. 192. 



Many of the unstriated muscular fibres from the true skin 
pass obliquely down from the surface of the dermis to the 
under side of the slanting hair-fol- 
licles. The contraction of these 
fibres erects the hairs, and by draw- 
ing the follicles to the surface and 
pulling in a little point of the skin, 
produces that roughness of the in- 
tegument called "goose-skin," or 
Cutis Anserina. The standing on 
end of the hair of the head, as the 
result of extreme fright, may be 
partly due to the contraction of 
such fibres, as well as to the action 
of the occipito-frontalis muscle. 

554. Each hair-follicle receives, 
in nearly all cases, the ducts of two 
Sebaceous, or Oil- Glands, which are 
situated in the dermis. They are 
found only where hairs exist. Each 
gland is a flask-shaped body, com- 
posed of from five to twenty little 
sacs, clustered around and leading 
into a common duct. These glands 
are lined by a fine epithelium, and 
the unctuous secretion first anoints 
the hair-bulb, and then oozes out 
upon the neighboring surface of the 
cuticle. The sebaceous glands are 
of considerable size. 

555. Immediately beneath the skin, over the whole surface 
of the body, there are a multitude of little glandular bodies, 
called Perspiratory, or Sweat Glands. Each gland consists of 
a minute, cylindrical spiral duct, which passes inward through 
the epidermis, and terminates in a globular coil, in the deeper 
meshes of the cutis vera. The opening of the duct upon the 
cuticle is called the "pore." This aperture is oblique in 



Fig. 192 (Leidy). Portion of a 
Hair from the Outer Part of 
the Thigh, magnified. 1, Shaft 
of the hair covered with trans- 
verse markings indicating the 
projecting edges of the cuticular 
scales. 2, Cortical substance at 
the end of the hair, broken up into 
coarse fibres, as the result of fric- 
tion of the clothing. 



280 ANATOMY, PHYSIOLOGY AND HYGIENE. 

direction, and possesses all the advantage of a valvular open- 
ing, preventing the ingress of foreign injurious substances to 



Fig. 193. 




Fig. 193. Oil-Glands and Ducts, magnified thirty-eight diameters. 1, A, Oil-gland 
from the scalp ; B, Its duct. 2, A, Two glands from the skin of the nose ; B, Common 
duct. 3, A, Oil-gland from the nose ; B, The duct filled with the peculiar animalculae 
of the oily substances ; the heads are directed inward. 4, A, Cluster of oil-glands around 
the shaft of the hair (C) ; B, Ducts. 

the interior of the duct or gland. These glands, coming in 
contact with the capillary blood-vessels, receive a watery- 
fluid (the perspiration) from the blood, having the following 
composition : 

Water 995.00 

Animal matters, with lime .10 

Chlorides of sodium and potassium and spirit extract.. 2.40 

Acetic acid, acetates, lactates and alcoholic extracts... 1.45 

Sulphates and substances soluble in water 1.05 

1000.00 

The formation of this watery fluid is constant, but usu- 
ally evaporation takes place as fast as it reaches the sur- 
face. This is called the "insensible transpiration" of the 
skin. 

556. The Nails are horny appendages of the skin, and 
correspond with the hoofs and claws of animals. They are 



THE ORGANS OF SPECIAL SENSE. 



281 



Fig. 194. 




flexible, translucent plates continuous with the epidermis, 
and rest on the depressed surface of the cutis vera, called the 
matrix, or bed. By maceration 
or severe scalding, the nail be- 
comes detached with the epi- 
dermis, even in life. 

The horny layer of the nail 
answers to the cuticle ; it is com- 
posed of numerous layers of flat- 
tened, nucleated cells, or scales, 
while the soft layer corresponds 
with the deep parts of the epi- 
dermis, and is made up of deli- 
cate polyhedral, nucleated cells. 
The nails increase in length by the constant addition of cells 
at the root ; they grow in thickness by the formation of cells 
on the under surface. This double development explains 
why nails are thickest at their most convex portion. 

For Physiology of the Skin, see 570. 



Fig. 194. A Section of the End op 
the Finger and Nail.— 4, Section of 
the last bone of the finger. 5, Fat, 
forming the cushion at the end of the 
finger. 2, The nail. 1, 1, The cuticle 
continued under and around the root 
of the nail, at 3, 3, 3. 



§ 50. Physiology of the Organs of Special Sense. — Primary 
Use of the Sense of Taste — Of Smell. Some of the Laws of Light. The 
Adaptation of the Eye to the Laws of Light. Cause of Shortsighted- 
ness — Of Long-Sightedness — Defect remedied. Functions of the Different 
Coats of the Eye. The Accessory Parts of the Eye. Hearing. Func- 
tion of the External Ear — Auditory Canal — Eustachian Tube — Cochlea 
and Semicircular Canals. Sounds reach the Fluid of the Labyrinth by 
Two Paths. Special Organ of the Sense of Touch. Functions of the 
Skin. Use of the Epidermis — Of the Cuticle — Of Cutaneous Papillce. 
Vessels of the Corium. Function of the Oil- Glands. Uses of Per- 
spiration. 

557. The primary use of the Sense of Taste is to guide 
animals in the selection of food, that noxious articles may 
not be introduced into the stomach. In man, this sense has 
been so abused and perverted by the introduction of stimu- 
lants and condiments, and the endless admixture of different 
articles of food, that the natural action seems to have been 
almost entirely superseded by acquired taste. This sense be- 

24* 



282 ANATOMY, PHYSIOLOGY AND HYGIENE. 

comes very acute by cultivation, as may be seen in those 
persons whose business it is to judge of the quality of certain 
articles by the taste ; as tasters of wine, tea, etc. The acute- 
ness of taste, however, varies in different persons according 
to the sapid bodies themselves. 

558. In man, the Sense of Smell is one of inferior im- 
portance. It furnishes the mind with but few ideas, and 
these are mostly subservient to his physical well-being. This 
sense leads us to avoid disagreeable odors or putrescent food, 
and when acute, to escape the injurious effects of many vapors 
which endanger health. 

559. The Structure of the Eye is beautifully adapted 
to the laws of light, a few of which it is necessary for us to 
notice. 

When light passes through a medium of unvarying density, 
the rays are in straight lines, but when it passes from a me- 
dium of one density into another of different density, they 
are refracted, or bent from a straight course, unless striking 
the medium perpendicularly, when they are unchanged. 

When light passes from one medium to another having a 
convex or concave surface, instead of a flat surface, a great- 
degree of refraction is produced, and the greater the curva- 
ture, the greater will be the amount of refraction. Fit a con- 
vex lens in an opening of the shutter of a darkened room ; 
the rays of light will cross each other in the lens, and an in- 
verted image of any object outside, as a tree or house, will be 
reflected upon a screen placed in the room, at a certain dis- 
tance in front of the lens. The exact point where the image 
is most distinct, is called the focus of the lens, and the dis- 
tance from the lens to the image, the focal distance. Now, 
in the eye, the pigment of the choroid coat gives the darkened 
room, the retina the screen, the pupil is the opening in the 
shutter, and the three humors are the curved lenses. The 
rays of light from any object cross each other, and an inverted 
image is formed on the retina. 

560. The shape of the cornea and aqueous humors is con- 
vexo-concave : the vitreous humor is concavo-convex : while 



THE ORGANS OF SPECIAL SENSE. 283 

the crystalline humor, or lens, is convexo-convex. It may 
at first seem that only one lens is necessary ; but light is com- 
posed of three primary colors, which are not equally refracted 
by the same lens, hence, there would be upon the edges of any 
single lens prismatic colors which would interfere with the 
distinctness of the image. This is obviated, by the adapta- 
tion of the curvatures of the lenses to the different colors. 

561. Suppose our object outside the darkened room to be 
at, that distance from the lens which will give a distinct image 
upon the screen ; now, if the object approach the lens, the 
image will be indistinct unless a more convex lens be substi- 
tuted for the first, or the distance between the lens and screen 
be increased. If the object recede, the image will be indis- 
tinct unless a less convex lens be substituted for the first, or 
the distance be lessened between the lens and screen. 

By a very nice adjustment, the eye is able to change the con- 
vexity of its lenses, and also to vary the focal distances, thereby 
adapting it to a wide range of vision. This is accomplished 
by the ciliary ligament and the muscular fibres connected 
with the ciliary processes, which change the curvature of the 
crystalline lens and the cornea by compression at the cir- 
cumference, and at the same time throw the lens forward, in- 
creasing the distance between it and the retina. The iris 
also aids, in adapting the eye to different distances. It con- 
tracts when viewing a near object, and dilates when viewing 
one more remote. 

562. When the cornea or crystalline lens is too convex, or 
the latter is too far from the retina, short-sightedness is pro- 
duced, and the defect is measurably remedied by the use of 
concave glasses ; when there is too little convexity, long- 
sightedness is the result, and convex glasses should be used. 
In old age, the humors being deficient in quantity, cause 
the flattening of the convex parts, hence the need of convex 
glasses. In the selection of glasses, the lens for each eye 
should be chosen separately, as the foci of the two eyes do 
not usually exactly correspond, therefore a lens that will suit 
one eye may strain the other. 



284 ANATOMY, PHYSIOLOGY AND HYGIENE. 

563. The Sclerotic Coat gives form to the eye, and serves for 
the attachment of the muscles which move the eye in various 
directions. The movements of the two eyeballs are always 
simultaneous and harmonious, but frequently not symmetrical. 
The function of the pigment of the choroid coat is to absorb all 
the luminous rays not necessary for vision. " If the sclerotic 
and choroid coats be carefully dissected off from the posterior 
part of the eye of an ox or any other large quadruped, leaving 
only the retina, and the eye so prepared be placed in a hole 
in a window-shutter, in a darkened room, with the cornea on 
the outside, all the illuminated objects of the external scene 
will be beautifully depicted, in an inverted position, on the 
retina. 

" Few spectacles are more calculated to raise our admira- 
tion than this delicate picture, which Nature has, with such 
exquisite art and with the finest touches of her pencil, spread 
over the smooth canvas of the expansion of the optic nerve — 
a picture which, though scarcely occupying a space of half 
an inch in diameter, contains the delineation of a boundless 
scene of earth and sky, full of all kinds of objects, some at 
rest and others in motion, yet all accurately represented as 
to their forms, colors and position, and followed in all their 
changes without the least interference, irregularity or con- 
fusion." 

564. The Accessory Parts of the Eye are of two kinds ; the 
one designed to protect the globe, or ball, the other to move it 
and give the required direction to fulfill its office. To enable 
the eye to move in all directions, without friction, it is placed 
on a cushion of fat which lines the bony orbit, thus protect- 
ing the globe on all sides except in front ; here are the Eye- 
lids, which by their alternate movement of depression and 
elevation spread over the front of the eyeball a watery 
secretion, by which its surface is constantly bathed, and its 
brilliancy and transparency kept unimpaired. 

By the contraction of a small ring-like muscle (the Orbicu- 
laris), the eyelids quickly draw together, and as they instantly 
separate, the secretion from the lachrymal gland is diffused 



THE ORGANS OF SPECIAL SENSE. 285 

over the conjunctiva. During life, this muscle is ever active 
and watchful for the safety of the eye. When a cinder or 
dust gets under the eyelids, it irritates the conjunctiva, and 
the movements of winking are very rapid. A viscid fluid is 
spread along the margin of the lid, which prevents the tears 
running over the eyelid. 

The Cilia, or Eyelashes, so interlace that protection is given 
the eye from light substances floating in the air. The Eye- 
brows assist in shading the eyes when exposed to strong light, 
and they lend expression to some emotions of the mind. 

565. Hearing is that function by which we obtain a 
knowledge of the vibratory motions of bodies, which consti- 
tute sounds. Independent of the sense of hearing, sound, as 
sound, has no existence in nature. 

566. The External Ear collects the waves of sound and re- 
flects them on the membrane of the tympanum ; this mem- 
brane facilitates their transmission to the chain of bones in 
the tympanum, to the walls of the cavity and to the air it 
contains; from the stirrup to the oval window; from this 
membrane the vibrations are communicated to the fluid of 
the labyrinth, until finally they are received by the expan- 
sion of the auditory nerve, by which the sensation is commu- 
nicated to the brain. 

567. The function of the Auditory Canal is to receive and 
conduct sonorous vibrations to the membrane of the tympa- 
num. This membrane is admirably adapted for the recep- 
tion of atmospheric sound-waves. In hearing, the air in the 
tympanic cavity plays an important part ; the design of the 
Eustachian tube is evidently to allow of equal atmospheric 
pressure upon both sides of the membrana tympani. The 
complicated communications of the internal ear contain the 
highly important parts of the organ of hearing. The Vesti- 
bule is the part essential to the simplest exercise of this sense. 
The Cochlea and Semicircular canals, or rather their contained 
membranous canals, receive vibrations through the mixed 
membranous and bony tympanic apparatus. It is asserted by 
some physiologists, that sound is communicated through the 



286 ANATOMY, PHYSIOLOGY AND HYGIENE. 

cranial bones ; the transmission, however, through the solid 
bones of the head, if it exists, is effected with difficulty. 

568. By this sense, therefore, we distinguish the quality, 
intensity, pitch, duration and direction of sonorous impulses. 
The delicacy with which these distinctions are appreciated 
varies in different individuals. The complication and finish 
of the auditory apparatus, and the perfection and delicacy 
of its action, are second only to those of vision. 

569. The Sense of Touch, though common to all parts 
of the Skin and adjoining mucous membranes, has for its 
special organ, the hand. It is most admirably adapted to its 
office, by reason of the number, size, arrangement, structure 
and abundant nervous supply of its papillae. 

570. The functions of the Skin are threefold : 1st, As a 
Protecting membrane ; 2d, As a Medium for the distribution 
of the tactile nerve-filaments ; and 3d, As an Eliminating 
organ. The extent of the skin, as it invests the entire sur- 
face of the body, following all its prominences and curves, 
its arrangement in layers, differing in structure, vitality and 
function, make it an external envelope of harmonious unity, 
in appointment and end. 

571. The uses of the Epidermis are various. It serves to 
cover and protect the delicate sensitive parts behind it; to 
prevent the too rapid escape of heat; and to restrain the 
evaporation of the fluids of the skin and its appendages, at 
the same time that it furnishes a medium through which 
those secretions can reach the surface of the body. 

572. The Cuticle is constantly destroyed and replaced, as 
is proved by the disappearance from the skin of such stains 
as those produced by nitrate of silver ; or the scales thrown 
off after some acute diseases, as scarlatina. The restoration 
of the cuticle is observed after the process of vesication by 
blisters, and in consequence of burns and scalds. By these 
means large patches of cuticle are removed ; but they are 
renewed in short time, under favorable circumstances. The 
pigmentary substance is also capable of rapid reproduction. 

573. The cutaneous Papillce serve to increase the nutritive 



THE ORGANS OF SPECIAL SENSE. 287 

and formative surface for the generation of the constantly 
wasting epidermis. 

574. In the Corium, or internal layer of the skin, resides 
vitality. Here the arteries of the skin penetrate from be- 
neath and end in a capillary network ; the veins emerging 
from the skin are more numerous and much larger than the 
arteries. The skin is abundantly supplied with nerves, but 
their mode of termination has not been accurately ascer- 
tained. 

575. The surface of the skin possesses the power of absorb- 
ing both liquids and vapors. The principal, if not sole, 
agents of this function on the surface of the body are the 
cutaneous Lymphatic vessels, which are active in proportion 
to the tenuity or absence of the cuticle. To a slight extent, 
the skin is a respiratory membrane in man, giving off car- 
bonic acid gas, and actually absorbing oxygen. 

576. The sebaceous matter from the Oil-glands anoints the 
hairs with oil in their progress of growth from the skin, and 
also imbues the cuticle, by which it is rendered repellent of 
water. The oiliness of the surface of the skin, occasioned by 
this material, permits the ready adhesion of dust and dirt, 
and necessitates the use of soap for the easy removal of its 
excess. This oily product often becomes inspissated and dis- 
tends the glands, most frequently in the face, and especially 
on the nose; and at the mouths of the ducts it becomes 
mixed with dust. When pressed out it assumes the spiral 
form of the duct ; hence it is commonly taken for a worm. 
In the healthiest individuals, the sebaceous matter contains a 
curious parasite, called the " pimple mite." 

577. The uses of the perspiration, or sweat, are twofold : 
1st, To free the system of a certain quantity of water ; and 
2d, To eliminate from the body certain special products of 
chemical changes. 

The quantity of perspiration exhaled by different parts of 
the body differs widely. Its general quantity is influenced 
both by intrinsic and extrinsic conditions ; thus, it is aug- 
mented by increased vascularity of the skin, by a higher 



288 ANATOMY, PHYSIOLOGY AND HYGIENE. 

temperature of the body, by a quicker circulation, and there- 
fore by exercise and effort generally. Perspiration may also 
be induced by additional covering of the body, and also by 
peculiar conditions of the nervous system. 

578. Of the external conditions which modify the quantity 
of perspiration, the condition of the atmosphere is most im- 
portant. Thus, in warm air the activity of the cutaneous 
circulation is increased, which increases the perspiration, 
whilst cold air has the opposite effect; again, dry air in- 
creases the perspiration, whilst damp air diminishes it. 
Simple warmth acts by increasing the vascular action 
through the skin, whilst dryness operates by maintaining a 
constant evaporation from this membrane ; on the other 
hand, cold diminishes the vascularity of the skin, and damp- 
ness of the air impedes evaporation. The combination of 
moisture with heat, however, increases the exhalation by the 
skin, which then appears in large drops. Large quantities 
of warm drinks also increase perspiration. 

Observation. — The skin is said to regulate the quantity of 
fluid given off by the kidneys, and the quantity of fluid left 
in reserve in the blood and soft tissues generally ; but the 
kidneys should rather be regarded as the true regulators. 
Observation shows that in cold weather the skin exhales less 
and the kidneys excrete more fluid ; while in warm weather 
the skin eliminates more and the kidneys less. 

579. The use of the non-vascular and insensible outgrowth 
of the epidermis, the hair, is protection ; and the function of 
the nails is not only protection, but support to the yielding 
softness of the flesh at the finger-tips. When they reach 
exactly to the extremities of the fingers, they then fulfill the 
intention for which they were made, by enabling the fingers 
to hold both small and hard substances, and to tear and peel 
off skins of vegetables or animals. They are called into action 
where nicety of execution is required in art. 



THE ORGANS OF SPECIAL SENSE. 289 



I 51. Hygiene of the Organs of Special Sense. — Perversion of 
the Sense of Taste — Of Smell. How the Eye should be Used. Cause 
of Amaurosis. The Effect of Continued Oblique Position of the Eye 
— Viewing Objects at Different Distances. Bathing the Eye — Re- 
moval of Dust. Causes of Defective Hearing. Parts Essential to Hear- 
ing. Clothing. Kind of Material for Clothing. Class of Persons that 
need more Clothing. Cleanliness of Clothing. Bathing — Modes of 
Bathing — Time for Baths — General Rules for Bathing — Water a Cura- 
tive Agent. Air Beneficial to the Skin. Effect of Light on the Skin. 
Treatment of Burns and Scalds — Of Corns — Of Frost-Bites. 

580. The Sense of Taste becomes perverted by the im- 
moderate use of stimulants and condiments and the endless 
admixture of different articles of food. These indulgences 
lessen the sensibility of the nerve. In children, this sense is 
usually acute, and their preference is for food of the mildest 
character. 

This sense is varied more than any other by the refine- 
ments of social life ; thus, the Indian's like or dislike regard- 
ing particular articles of food generally extends to every 
individual of the tribe, but among civilized men no two per- 
sons are alike in all their tastes. 

581. The Sense of Smell may become impaired by being 
frequently and powerfully stimulated by pungent articles, as 
" smelling salts ;" also catarrh, or any influence that thickens 
the mucous membrane or renders it dry, diminishes the sensi- 
bility of the nerve of smell. Hence, the sense becomes very 
obtuse in persons addicted to the pernicious habit of "snuff- 
taking." 

582. The Eye is a delicate organ, requiring care to preserve 
it in health ; like other organs of the body, it should be exer- 
cised and then rested. The observance of this rule is par- 
ticularly needful to those whose eyes are predisposed to 
inflammation. If the eye be used too long at one time, it 
becomes wearied and the power of vision diminished. On 
the contrary, if not called into exercise, its functions are 
enfeebled. 

583. Sudden transitions of light should be avoided. The iris 

25 N 



290 ANATOMY, PHYSIOLOGY AND HYGIENE. 

enlarges or contracts according to the degree of light, but the 
change is not instantaneous. Hence the imperfect vision in 
passing from a strong to a dim light ; an overwhelming sensa- 
tion is experienced when passing from a dimly-lighted apart- 
ment to one brilliantly illuminated. A common cause of 
Amaurosis, or paralysis of the retina, is using the eye for a 
long time in a very intense light. 

584. Long-continued oblique position of the eye should be 
avoided, or it may produce an unnatural contraction of the 
muscles called into action, producing squinting or strabis- 
mus. The vision of a cross eye is always defective, as only 
one eye is used in viewing the object toward which the atten- 
tion is directed. The defect is remedied by a surgical opera- 
tion. Children should not be allowed to imitate the " cross 
eye," as what is intended to be but temporary, may become 
permanent. 

585. The eye of the child should be trained to view objects at 
different distances. The ciliary muscles are as capable of 
education as any others, and may be made to act very effi- 
ciently in adapting the lenses to view near or remote objects. 
Care on the part of the instructor and parent regarding the 
distance from the eye at which the child should hold his 
book or work would save many cases of defective vision. 

586. Bathing the eye in tepid or cold water is beneficial; 
provided the eye be gently wiped and usually toward the 
inner angle ; also, to remove the secretion from the lachrymal 
gland that sometimes collects at this angle, as it contains 
saline matter. 

Observation. — Particles of dust or cinders should be removed 
from the eye by means of soft linen or silk. If the substance 
is concealed beneath the upper lid, take a smooth rod, like a 
knitting needle, place it over the upper lid in contact with 
and just under the edge of the orbit ; hold it firmly by means 
of the lashes, turn the lid gently back over the pencil or 
needle, and remove the intrusive substance. If unsuccessful, 
too many attempts should not be made, as inflammation may 
be induced, but consult a surgeon immediately. 



THE OKGANS OF SPECIAL SENSE. 291 

587. The Sense of Hearing, like the other senses, is capable 
of great improvement. By cultivation, the blind are able to 
judge with great accuracy of the distance of bodies in motion, 
and even of the height of buildings. The Indian will distin- 
guish sounds inaudible to the untrained ear. 

588. Hearing may be impaired by the destruction of the 
membrane of the tympanum. The obstruction of the Eusta- 
chian tube is not unfrequently the cause of defective hearing. 
By its closure, the vibratory effect of the air within the tym- 
panum is diminished in the same manner as in the closure 
of the side of a drum. Enlarged tonsils, inflammation of the 
fauces and nasal passages, often attend and follow colds and 
attacks of scarlet fever, etc. For such deafness, remedial 
means should be directed by a skillful physician. 

Observation.— -The nostrums for the cure of deafness are 
usually of an oily character, and may be useful in cases of 
defective hearing caused by an accumulation of wax in the 
external canal of the ear ; but a few drops of any animal oil 
will serve the purpose as efficiently. 

589. In hearing, the integrity of the drum of the ear is not 
absolutely essential for the due performance of the function. 
The loss of the small bones does not necessarily cause deafness 
unless the stirrup is diseased ; but if the auditory nerve or 
membranous vestibule becomes diseased, there is no remedial 
agent for the loss of hearing. 

590. The Hygiene of the Skin, the chief organ of the Sense 
of Touch, holds important relation to the general health of 
the body. To maintain its healthy action in every part, 
attention must be given to Clothing, Bathing, Light and Air. 

591. Clothing is chiefly useful in preventing the escape 
of too much heat from the body, and in protecting the body 
from exposure to the evil effects of a varying temperature of 
the atmosphere. In selecting and applying clothing, the fol- 
lowing should be observed : 

592. The material for clothing should be a bad conductor of 
heat. As air is a non-conductor, material should be chosen 
which is capable of retaining much air in its meshes ; and as 



292 ANATOMY, PHYSIOLOGY AND HYGIENE. 

moisture increases the conducting power, the material should 
not be such as will absorb or retain moisture. Furs retain 
much air in their meshes and absorb scarcely any moisture, 
and consequently, are well adapted to those subject to the 
great exposures of very cold climates. Woolen cloth, next to 
furs and eider down, retains the most air and absorbs the 
least moisture, hence it is a good article of apparel for all per- 
sons, unless too irritable to an over-sensitive skin. In that 
case, the flannel may be lined w r ith cotton, or silk may be 
substituted. When of sufficient body or thickness, silk is a 
good article for inner clothing, excepting when it produces 
too much disturbance of the electricity of the system. Next 
to these articles, cotton is well adapted for garments worn 
next the skin. Linen should never be worn by persons in 
any way enfeebled, even in warm weather or in hot climates. 
It is a good conductor of heat and readily absorbs moisture ; 
hence, with such covering, the body is surrounded by a layer 
of moisture instead of air. 

593. The clothing should be both jwrous and loosely fitted. 
The necessity of porous clothing is seen in the wearing of 
India-rubber overshoes. In a short time the hose and under- 
boot become damp from retained perspiration. The residual 
matter thus left in contact with the skin is reconveyed into 
the system by absorption, causing headache and other dis- 
eases. Unimpeded transpiration, and a layer of air secured by 
loose clothing, enable the skin to imbibe oxygen, which gives 
it tone and vigor. 

Observation. — As the design of additional clothing is to 
enclose a series of strata of warm air, we should, in going 
from a warm room into cold air, put on our extra covering 
some time previous to going out, that the layers of air which 
we carry with us may be warmed by the heat of the room, 
and not borrowed from the heat of the body. 

594. The clothing must be suited to the state of the atmosphere 
and to the condition of the individual. Sudden changes of 
temperature should be regarded ; but it is usually unsafe to 
make changes from thick to thin clothing, excepting in the 



THE ORGANS OF SPECIAL SENSE. 293 

morning, when the vital powers are in full play. The even- 
ing usually demands an extra garment, as the atmosphere is 
more cool and damp, and we have less vital energy than in 
the early part of the day. 

Observation. — Many a young lady has laid the foundation 
of a fatal disease by exchanging the thick dress, warm hose 
and*shoes, for the flimsy fabric, thin hose and shoes which 
are considered suitable for the ball-room or party. All sud- 
den changes of this kind are attended with hazard, which is 
proportionate to the weakness or exhaustion of the system 
when the change is made. 

595. The child and the aged person require more clothing 
than the vigorous person of middle age. Judging from ob- 
servation, we should infer that children needed less clothing 
than adults. The exposure to which the vain and thoughtless 
mother subjects her child very frequently lays the foundation 
for future disease. The system of "hardening" children, of 
which we sometimes hear, is as inhuman as it is unprofitable. 
To make the child robust and active, he must have nutritious 
food at stated hours, free exercise in the open air, and be 
guarded from the cold by proper apparel. Those who have 
outlived the energies of adult life also need special care re- 
garding a proper amount of clothing. 

596. When a vital organ is diseased, more clothing is needed. 
In consumption, dyspepsia, and even headache, the skin 
usually is pale and the extremities cold, because less heat is 
generated. Persons suffering from these complaints need 
more clothing than those with healthy organs. 

597. Persons of active habits need less clothing than those of 
sedentary employment. Exercise increases the circulation of 
the blood, consequently, the vital activities become more 
energetic, and more heat is produced. We need less clothing 
when walking than when riding. 

598. The clothing should be kept clean. Some portion of 
the transpired fluids of the body must necessarily be ab- 
sorbed by the clothing. Hence, warmth, cleanliness and 
health require that it should be frequently changed and 

25 * 



294 ANATOMY, PHYSIOLOGY AND HYGIENE. 

thoroughly washed. Under-garments worn through the day 
should not be worn through the night, nor the reverse. When 
taken from the body, such garments should not be hung in 
the closet or put into the drawer, but exposed to a current of 
fresh air. 

The covering of beds should be thoroughly aired every 
morning, and frequently renewed. 

599. Damp clothing is injurious. All articles from the 
laundry should be well aired before being worn. When the 
clothing is wet by accident or exposure, it should be changed 
immediately, unless the person is exercising so vigorously as 
to prevent the slightest chill. When the exercise ceases, the 
body should be rubbed with a dry crash towel till a thorough 
reaction takes place. 

Beds and bedding that have not been used for some weeks 
become damp, and should be dried before use. A hostess 
cannot be guilty of a more inhospitable act than that of 
sending her guest to her fine guest-chamber, to occupy a bed 
which has been long unused. 

600. Bathing is indispensable to sound health as well as 
to cleanliness. The skin soon becomes covered with a mix- 
ture of perspirable matter, oil and dust, which, if allowed to 
remain, interferes with the action of the skin as an excretory 
organ. This increases the action of the lungs, kidneys, liver, 
etc., which take upon themselves the excretory work which 
the skin fails to perform. By overwork they soon become 
diseased, and if it is continued, the result will be consumption 
and other diseases of the vital organs. Again, obstruction 
of the pores will prevent respiration through the skin, and 
deprive the blood of one source of its oxygen and one outlet 
of its carbonic acid. 

601. Bathing gives tone and vigor to the internal organs. 
When cool water is applied to the body, the skin instantly 
shrinks and the whole of its tissue contracts. This contrac- 
tion diminishes the capacity of the blood-vessels, and a por- 
tion of the blood is thrown upon the internal organs. The 
nervous system is stimulated and communicates its stimulus 



THE ORGANS OF SPECIAL SENSE. 295 

to the whole system. This causes a more energetic action of 
the heart and blood-vessels, and a consequent rush of blood 
back to the skin. This is the state termed reaction, the first 
object and purpose of every form of bathing. By this re- 
action the internal organs are relieved, respiration is light- 
ened, the heart is made to beat calm and free, the tone of the 
muscular system is increased, the appetite is sharpened, the 
mind more clear and strong, and the whole system seems to 
possess new power. Regularity in bathing is necessary to 
produce permanently good effects. 

602. The simplest modes of bathing are by means of the 
sponge or the shallow baths. The body may be quickly 
sponged over, wiped dry and followed by friction. The 
water may be warm or cold. If cold, the bath should be 
taken in the early part of the day, and followed by exercise. 
If exercise cannot be taken, the individual should rest under 
covering. The warm bath should usually be taken just be- 
fore retiring. If taken at other hours, it should be followed 
by rest from half an hour to one hour under proper covering. 

603. The shallow bath, in which the body is partly immersed 
in water, is very pleasant and safe, provided the bather exer- 
cises in it by vigorous rubbing and does not remain too long. 
For a cold bath it is not often safe to exceed five minutes, 
and with delicate persons the time should rarely exceed two 
or three minutes. A bath is considered cold when below 
75° ; temperate, from 75° to 85° ; tepid, 85° to 95°. This 
and every other form of bath should be followed by thorough 
friction with a coarse towel or flesh-brush. 

604. The frequency of bathing 7nust depend upon the con- 
dition and occupation of the individual. Daily bathing may 
be practiced with profit by most persons, but to the studious 
and sedentary it is in most cases absolutely indispensable. 

605. The hour for ablution is of importance. It should 
neither immediately precede nor follow a meal. The same is 
true of severe mental and muscular exercise. The bath is 
less beneficial in the afternoon than the forenoon. The best 
time for cold baths is two or three hours after breakfast. 



296 ANATOMY, PHYSIOLOGY AND HYGIENE. 

The system is then at " flood-tide," while from that time till 
the retiring hour the tide is ebbing ; hence, the worst time for 
a cold bath is at bed-time. For those who cannot choose 
their time, the hour of rising will answer very well — that is, 
for many persons, especially if they become accustomed to 
the use of water by beginning at another and a better hour. 
If the mind and body are brightened by the early bath, and 
an exhilaration follows, the bath is beneficial ; if on the con- 
trary, languor follows, and the skin looks blue or too pale, it 
is injurious. That the bath is to be followed by exercise 
must not be forgotten. 

606. In diseases of the skin, and many chronic ailments of 
the internal organs, bathing is a remedial measure of great 
power. In disease which has baffled the skill of physicians 
depending wholly upon internal remedies, the effect of a 
systematic course of baths is often surprising. Like other 
curative means, the baths should be directed by those who 
thoroughly understand the use of water as a remedial agency. 
Matters of diet, exercise, etc., require adaptation to the treat- 
ment of the particular case. Those who desire the full benefit 
of these means must avail themselves of the appliances of a 
well-conducted water-cure establishment. 

607. A few simple rules must be observed in bathing. The 
face and head should be wet in cold water before the bath. 
Cool baths should not be taken when the person is chilly, 
perspiring or greatly fatigued. All general baths should be 
taken briskly, the skin well rubbed and quickly dried, fol- 
lowed by a healthy glow over the .whole body. Exercise 
should immediately follow all baths. Warm baths at night 
should be taken just before retiring; at other hours they 
should be followed immediately by rest, under coverings, 
after which exercise should be taken. 

Soap is admirably adapted to the removal of dirt from 
the skin, but if it is too freely used on the general sur- 
face of the body, it dissolves the oily exudation of the seba- 
ceous glands, leaving the skin dry or wrinkled. The ex- 
ternal epithelial cells may be removed too rapidly when 



THE ORGANS OF SPECIAL SENSE. 297 

soap is used in excess, consequently the skin is not properly 
protected. 

608. Pure Air is an agent of great importance in the 
functions of the skin. It imparts to this membrane some 
oxygen, and receives from it carbonic acid gas. It likewise 
removes perspiration and portions of the oily secretion. 

609. Light exercises a very salutary influence upon the 
skin. It is no less essential to the vigor of animal than of 
vegetable life. Dwelling-houses should be built with refer- 
ence to the free admission of sunlight and air into all occu- 
pied rooms. The dark, damp rooms so much used by indi- 
gent families and domestics in cities and large villages are 
fruitful causes of vice, poverty and suffering. Ladies often 
suffer seriously from too much exclusion of sunlight. Ex- 
cepting in very warm w r eather, they should practice sitting 
or exercising in the full sunshine of the out-door world. 

610. Burns and Scalds. When blisters are formed, the 
epidermis is separated from the other layer of the skin by 
the effusion of serum ; this fluid should be let free by punc- 
turing the cuticle, care being taken not to remove the thin 
raised skin, as it makes the best possible protection to the 
sensitive, inflamed tissues beneath. When this thin outside 
layer of skin is removed, immediately cover the denuded 
parts with wheat flour, or a plaster made of lard and bees'- 
wax or the white of an egg ; in a word, substitute a cuticle 
to protect the exposed nerves from the air. When dressings 
are applied, they should not be removed until they become 
dry and irritating. 

To prevent vesication, when only a small patch of the 
skin is scalded or burned, apply steadily cold water until the 
smarting pain ceases ; then put on a simple dressing, "not to 
take out the fire or heal it," but to protect the injured 
membrane. 

611. When the epidermis, in particular spots, is exposed to 
excessive pressure or friction, it becomes too much thickened, 
producing Corns. They are not necessarily confined to the 
feet, but are produced in front of the clavicle of the soldier 

N* 



298 ANATOMY, PHYSIOLOGY AND HYGIENE. 

from the pressure of his musket, or on the knee of the cobbler. 
The pain of the callosity is due to their exciting inflamma- 
tion in the sensitive dermis upon which they press. Remove 
the pressure, and the affected part is restored to its normal 
state. 

612. Frost-Bite is usually manifested first upon parts un- 
protected by covering, as the face or ears, and especially the 
nose. In such case, the skin first becomes red, from con- 
gestion of the dilated capillary vessels ; next it becomes 
bluish, from arrest of the circulation ; and afterward of a 
dead white hue. To restore circulation and sensibility, rub 
the frozen part with snow or apply iced water. Keep the 
sufferer at first in a cold room, and let the return to a higher 
temperature be gradual and cautious, or gangrene may super- 
vene. The Chilblain is not produced by the action of cold, 
but by the effect of heat on the chilled extremity. 



APPENDIX. 



CHAPTEE XIII. 

CARE OF THE SICK. 

§ 1. In every home, however humble or dignified, woman is 
usually the Nurse. Nature seems to have endowed her in an 
especial manner to minister at the couch of disease and suffering. 
To be a good nurse requires a high type of womanhood ; she 
should have both mental and physical power, blended with integ- 
rity and Christian trust. 

If "good nursing is half the cure," how important that the 
daughter be early taught how to prepare drinks and nourishments ; 
to administer medicine ; and to perform the varied and important 
duties of the faithful nurse ! 

The physician well knows that his attentions upon the sick are 
quite unavailing unless the nurse obeys his directions. For a 
nurse, or immediate relatives or friends of the sick, to put their 
judgment in opposition to that of the physician, is not only arro- 
gant, but endangers the patient. The room for the sick should be 
selected where sunlight may enter, and as far from external noise 
as possible. It is poor economy, not to say unkind, to keep a sick 
man in a small, ill-arranged bed-room, when a more spacious and 
airy room is kept for only occasional "callers." All superfluous 
furniture should be removed from the sick room. 

In the first stages of disease, it is always proper treatment to 
rest both body and mind, It is wrong to tempt the appetite of a 
sick person ; the disinclination for food is the warning of Nature 
that the system cannot well digest it. 

The beneficial effects of bathing can hardly be over-estimated, 
but the mode of the bath should be directed by the medical ad- 
viser. The best time, however, for bathing is when the patient 
feels most vigorous and freest from exhaustion. Care is necessary 
to wipe dry the skin, particularly between the fingers and toes, and 

299 



300 APPENDIX. 

also the flexions of the joints. Friction from a brush, moreen 
mitten or a dry flannel that has been saturated with salted water 
tends to relieve restlessness in patients. Air-baths have a tran- 
quillizing influence. 

Quiet should reign in the sick room. No more persons should 
enter or remain in it than the welfare of the patient demands. It 
is the duty of the physician to direct when visitors should be ad- 
mitted or excluded, and the nurse should enforce the directions. 
The movements of the attendants should be gentle : no bustling to 
" clear up the room" at a fixed time ; this should be done quietly 
and when it will give the least annoyance to the sick. (It may be 
necessary to use a damp cloth in dusting the furniture, also the 
carpet, especially if the patient has disease of the lungs. ) Creak- 
ing hinges should be oiled ; shutting doors violently and heavy 
walking avoided. All unnecessary conversation should be deferred. 
If a colloquy must be carried on, let the tone be so high that the 
patient, if interested, can thoroughly comprehend it. 

The making of the bed is often badly conducted. All bunches 
should be removed, the material of the bed laid even and a thin 
quilt spread smoothly over a mattress. When convenient, have the 
head of the bed northerly (182), and so situated, at least, that the 
sick man may look on something more pleasurable than a table of 
glasses and phials. A nurse should never manifest impatience in 
arranging the pillows, but try to adapt them to the comfort of the 
weary patient. 

All utensils employed in the sick room should be kept clean. 
Water designed for the patient to drink should not stand long in 
an open glass or pitcher, but be given fresh from a spring or well. 
A very sick person is fatigued by being raised to receive drinks, 
hence, a bent tube or a cup with a spout should be used. 

Both the apparel and the bed-linen should be changed more fre- 
quently in sickness than in health, and oftener in acute than in 
chronic diseases. All clothing, whether from the laundry or 
bureau, should be well dried and warmed by a fire previous to 
being put on the bed or the patient. 

No agent is of more importance to the sick room than pure air ; 
hence, the nurse, with all convenient speed, should remove every- 
thing that can emit an unpleasant odor. She should be chary of 
keeping ripe fruit or bouquets of flowers any length of time in the 
sick chamber. W T hen a disinfectant is needed, procure at the 
druggist's, chloride of lime. To change quickly and effectively the 



I 



APPENDIX. 301 

air of the sick room, cover the patient's bed with an extra blanket 
and closely envelop his head and neck, except the mouth and 
nose ; the door and windows can then be safely opened for a short 
time without detriment. After the windows are closed, retain the 
extra coverings on the patient until the room is of proper warmth. 
Unless duly protected, the patient should never feel currents of air, 
although fresh air should be constantly admitted into the sick 
room. 

A well-adjusted thermometer is indispensable, as the feelings of 
the patient or nurse are not to be relied on as a true index of the 
temperature of the room. Regulating the warmth of the patient 
is one of the many duties of the nurse. There is a " sweating tem- 
perature ;" w r hen this is exceeded, perspiration will cease if it has 
been present ; or that it will not take place during a high tem- 
perature. The patient should no more be allowed to complain of 
too much heat, without an attempt at its reduction, than he should 
be permitted to remain chilly when it is possible to remove it. 

The nurse should not confine herself to the sick room longer 
than six hours at a time. She should exercise daily in the open 
air, also eat and sleep as regularly as possible. No doubts or fears 
of the patient's recovery, either by a look or by a word, should be 
communicated by the nurse in the chamber of the sick ; this duty 
devolves upon the physician. 

Medicines assist the natural powers of the system to remove dis- 
ease. They should be given regularly, judiciously and with a 
cheerful manner. Life itself is often at the mercy of the nurse, 
and depends on the faithful discharge of her duty. 

Drinks have a more decided influence upon the system than is 
generally admitted ; hence, the nurse should never depart from 
the quality of the drink, nor even exceed the due or prescribed 
quantity. Giving "herb teas" without the sanction of the plvy- 
sician may cause serious evil. 

The food of the sick should be prepared in the neatest and most 
careful manner, and the nurse ought to obey implicitly the phy- 
sician's directions about diet. When a patient is convalescent, the 
desire for food is generally strong ; great care, firmness and pa- 
tience is required, that the food be prepared suitably and given at 
the proper time. 

We append a few modes of preparing nourishment for the sick. 

Crust Coffee. — Take light, sweet bread or crackers, and brown 
them thoroughly as you would coffee berry ; when wanted for use, 
26 



302 APPENDIX. 

pour over boiling water (the crusts will admit of several replenish- 
ings of boiling water) ; add sugar and cream to suit the condition 
of the patient. 

Gruels. — Corn meal requires to be boiled several hours to be 
suitable nourishment for the sick. The mode of preparing gruel 
should be suited to the case and directed by the physician. Wheat, 
or oat-meal, farina and sago, can be prepared in less time, though 
they must be well cooked. Add salt while cooking. 

Egg Gruel. — Take the yolks of two eggs, boiled hard, and with 
a knife reduce them to a fine powder ; beat this into a flour gruel 
made of new milk ; salt and spices may be added if the condition 
of the patient admits. 

Beef Tea. — Meat contains principles that may be extracted, 
some by cold, others by warm, and others, again, by boiling, water; 
it should be cut very fine, and submitted for three hours each time, 
in succession, to half its weight of cold, of warm and of boiling 
water; the fluids strained from the first and second macerations 
are to be mixed with that strained from the boiling process, and 
the mixture should be brought to a boiling heat to cook it — the fat 
skimmed off ; add a few drops of some acid, with salt, for a flavor. 

\ 2. The duty of the Watcher is scarcely less responsible than 
that of the nurse ; and, like the nurse, she should ever be cheerful, 
kind, firm and attentive in the presence of the patient. 

The watcher should be prompt, and reach the house of the sick 
at an early hour ; before entering the sick room, she should eat a 
simple, nutritious supper, and also during the night take some 
plain food. She should be furnished with an extra garment, as a 
heavy shawl, to wear toward morning, when the system becomes 
exhausted. 

The directions about the sick, especially the administration of 
medicine, should be written for the temporary watcher. Whatever 
may be wanted during the night should be brought into the sick 
chamber or the adjoining room before the family retires to sleep, 
that the slumbers of the patient be not disturbed by haste or 
searching for needed articles. 

Sperm candles are preferable for the sick room. Kerosene, in 
burning, emits a disagreeable odor, often annoying to the patient. 
All lights ought to be so arranged as not to be reflected in the part 
of the room where the sick lie. 

It is not necessary that watchers make themselves acceptable to 



APPENDIX. 303 

the patient by exhausting conversation. If two watchers are 
needed, it is more imperative that they refrain from talking, and 
particularly whispering. 

Most sick persons have special need of nourishment about four 
or five o'clock in the morning. 

When taking care of the sick, light-colored clothing should be 
worn in preference to dark apparel, especially if the disease is 
of a contagious character. It is always safe for the watcher to 
change her apparel worn in the sick chamber before entering upon 
her family duties. Disease is often communicated by the clothing. 

It can hardly be expected that the farmer who has been laboring 
hard in the field, or the mechanic who has toiled during the day, 
is qualified to render all those little attentions that a sick person 
requires. Hence, would it not be more benevolent and economical 
to employ and pay watchers who are qualified by knowledge and 
training to perform this duty in a faithful manner, while the 
kindness and sympathy of friends may be practically manifested 
by assisting to defray the expenses of these qualified and useful 
assistants ? 



POISONS AND THEIR ANTIDOTES. 

I 3. Poisoning, either from accident or design, is of such fre- 
quency, that every household should keep some available remedy, 
and every person should know what to do in such alarming contin- 
gencies. Nearly every poison has its antidote, which, if used at 
once, may prevent much suffering and even death. 

When known that poison has been taken into the stomach, the 
first thing is to evacuate it by the use of the stomach-pump or an 
emetic, unless vomiting takes place spontaneously. 

As an emetic, ground Mustard mixed in warm water is always 
safe. Take one tablespoonful to one pint of warm water. Give the 
patient one-half in the first instance, and the remainder in fifteen 
minutes, if vomiting has not commenced. In the interval, drink 
copious draughts of warm water. Irritate the throat with a feather 
or the finger, to induce vomiting. After vomiting has begun, give 
mucilaginous drinks ; such as flaxseed tea, gum-arabic water, or 
slippery elm. 

If the patient is drowsy, give a strong infusion of cold coffee, 
keep him walking, slap smartly on the back, use electricity ; it may 
be well to dash cold water on the head, to keep the patient awake. 



304 



APPENDIX. 



After the poison is evacuated from the stomach, to sustain vita) 
action, give warm water and wine or brandy. If the limbs are cold, 
apply warmth and friction. 

In ALL cases of poisoning, call immediately a physician, as the 
after-treatment is of great importance. 



> (Water Hemlock). 



Poisons. 
Aconite (Monkshood). 
Belladona (Deadly Night-Shade) 
Bryony. 
Camphor. 
Conium ' 
Cicnta 
Croton Oil. 
Digitalis (Foxglove). 
Dulcamara (Bitter-Sweet) . 
Gamboge. 

Hyoscyamus (Henbane). 
Laudanum. 
Lobelia. 
Morphine. 
Opium. 
Paregoric. 

Sanguinara (Blood-Root). 
Savin Oil. 

Spigelia (Carolina Pink). 
Stramonium (Thorn Apple). 
Strychnine (Nux Vomica). 
Tobacco. 



Antidotes or Remedies for Poisons. 



For Vegetable poisons give an emetic 
of Mustard; drink freely of warm 
water ; irritate the throat with a 
feather to induce vomiting. Keep 
the patient awake until a phy- 
sician arrives. 



Arnica. 

Prussic Acid. 

Bitter Almonds (Oil of). 

Laurel Water. 

Ammonia (Hartshorn). 

Potash. 

Soda. 



Iodine. 



Vinegar and water. 

Drink, at once, one teaspoonful of 
Water of Hartshorn (ammonia) in 
one pint of water. 

Antidote is Vinegar or Lemon Juice; 
followed with sweet, castor or lin- 
seed oil. Thick cream is a sub- 
stitute for oil. No emetic. 



| Starch or wheat flour beat in water. 
/ Take a Mustard emetic. 



APPENDIX. 



305 



Poisons. Antidotes or Remedies for Poisons. 

lA \ /y .-. 1 .._. ' N \ Take at once, a Mustard emetic; 

Saltpetre (Nitrate of Potassa). , . , . , . 

nwv a u 4 /at-, i <■ a j \ "f drink copious draughts of warm 
Chili Saltpetre (Nitrate of Soda). ^*. . . , ., 

•/ water ; followed with oil or cream. 

"| Two teaspoonfuls of table salt (chlo- 
Lunar Caustic (Nitrate of Silver), [• ride of sodium) mixed in one pint 

J of water. 



Corrosive Sublimate (bug poison). 
White Precipitate. 
Red Precipitate. 
Vermilion. 



Arsenic. 

Cobalt (fly powder). 

King's Yellow. 

Ratsbane. 

Scheele's Green. 



Acetate of Lead (Sugar of Lead). 

White Lead. 

Litharge. 



Antimony (Wine of). 
Tartar Emetic. 



Beat the Whites of six Eggs in one 
quart of cold water; give a cup- 
ful every two minutes, to induce 
vomiting. A substitute for white 
of eggs is soap-suds slightly thick- 
ened with wheat flour. Emetics 
should not be given. 

Use a stomach-pump as quickly as 
possible, or give a Mustard emetic 
until one is obtained. After free 
vomiting, give large quantities 
of Calcined Magnesia. The anti- 
dote for Arsenic is Hydrated Per- 
oxide of Iron. 

Use a Mustard emetic; followed by 
Epsom or Glauber Salts. The 
antidote is diluted Sulphuric Acid. 

The antidote is ground Nutgall. A 
substitute, oak or Peruvian bark ; 
followed by a teaspoonful of pare- 
goric. 



Pearl-ash. 

Ley (from wood-ashes). 

Salts of Tartar. 



Sulphuric Acid (Oil of Vitriol). 
Nitric " (Aquafortis). 

Muriatic " (Marine). 
Oxalic Acid. 

26* 



•\ Drink freely of Vinegar and water ; 
V followed with a mucilage, as flax- 
i seed tea. 

* Drink largely of water or a muci- 
lage. It is important that some- 
thing be given quickly, to neu- 
tralize the acid. The antidote is 
Calcined Magnesia. Chalk, lime, 
strong soap-suds are substitutes 
for magnesia. 



306 



APPENDIX. 



Poisons. 

Matches (Phosphorus). 
Kat Exterminator. 

Verdigris. 
Blue Vitriol. 



Sting of Insects. 



Charcoal Fumes. 

Gas or Burning Fluid. 



Antidotes or Remedies for Poisons. 
-\ Give two tablespoonfuls of Calcined 
>■ Magnesia; followed by mucilag- 
J inous drinks. 

}The antidote is Cooking Soda y or 
White of Eggs. Drin k milk freely. 

Ammonia, or cooking soda moistened 
with water, applied in the form 
of a paste. The wound may be 
sucked, followed by applications 
of w r ater. 



1 Fresh air and Artificial Respira- 
/ tion. 



For the Treatment of Wounds and Arrest of Hemorrhage (363). 
For the Recovery of Asphyxiated Persons (430). 
For Burns and Scalds (610). 






GLOSSARY. 



Ab-do/men. [L. abdo, to hide.] That part 
of the body which lies between the tho- 
rax and the bottom of the pelvis. 

Ab-dom^in-is. Pertaining to the abdomen. 

Ab-duc'tor. [L. abduco, to lead away.] A 
muscle which moves certain parts, by 
separating them from the axis of the 
body. 

A-ce-tab^u-lum. [L. acetum, vinegar.] The 
socket for the head of the thigh-bone ; 
an ancient vessel for holding vinegar. 

A-ce'tic. [L. acetum, vinegar.] Relating 
to acetic acid. This is always composed 
of oxygen, hydrogen and carbon in the 
same proportion. 

A-chii/lis. A term applied to the tendon 
of the two large muscles of the leg. 

A-cro^mi-on. Gr. aicpos, akros, highest, and 
to/mo?, omos, shoulder.] A process of the 
scapula that joins to the clavicle. 

Ad-duc/tor. [L. adduco, to lead to.] A 
muscle which draws one part of the 
body toward another. 

Al-bu^men. [L. albus, white.] An animal 
substance of the same nature as the 
white of an egg. 

A-lu'min-um. [L.] The name given to the 
metallic base of alumina. 

Ai/ve-o-lar. [L. alveolus, a socket.] Per- 
taining to the sockets of the teeth. 

Am-mo/ni-a. An alkali. It is composed 
of three equivalents of hydrogen and one 
of nitrogen. 

Am-phi-ar-thro^sis. [Gr. afx<f>t, amphi, 
both, and ap0p<o5ia, arthrodia, well arti- 
culated.] A mixed articulation. 

A-nas/to-mose. [Gr. ava, ana, through, 
and a-TOjxa, stoma, mouth.] The com- 
munication of arteries and veins with 
each other. 

An-a-tom/i-cal. Relating to the parts of 
the body when dissected or separated. 



A-nat^o-mt. [Gr. ava, ana, through, and 
rofxr,, tome, a cutting.] The description 
of the structure of animals. The word 
anatomy properly signifies dissection. 

An-gi-oi/o-gy. [Gr. ayyeiov, angeion, a 
vessel, and Aoyos, logos, discourse.] A 
description of the vessels of the body; 
as the veins and arteries. 

An/gu-li. [L. angulus, a corner.] A term 
applied to certain muscles on account 
of their form. 

An-i-xMAi/cu-l^. [L. animalcula, a little 
animal.] Animals that are only per- 
ceptible by means of a microscope. 

An'nu-lar. [L. annulus, a ring.] Having 
the form of a ring. 

An-ti^cus. [L.] A term applied to certain 
muscles. 

A-ort/a. [Gr. aoprrj, aorte; from at\p, aer, 
air, and rrjpeto, tereo, to keep.] The great 
artery that arises from the left ventricle 
of the heart. 

Ap-o-neu-ro/sis. [Gr. airo, apo, from, and 
vevpov, neuron, a nerve.] The mem- 
branous expansions of muscles and ten- 
dons. The ancients called every white 
tendon neuron, a nerve. 

Ap-pa-ra/tus. [L. apparo, to prepare.] An 
assemblage of organs designed to produce 
certain results. 

Ap-peni/ix. [L. ad and pendeo, to hang 
from.] Something appended or added. 

A/que-ous. [L. aqua, water.] Partaking 
of the nature of water. 

A-rach^noid. [Gr. apaxvi), arachne, a spider, 
and eiSos, eidos, form.] Resembling a 
spider's web. A thin membrane that 
covers the brain. 

Ar/bor. [L.] A tree. Arbor vitse. The 
tree of life. A term applied to a part of 
the cerebellum. 

Ar/te-rt. [Gr. arjp, aer, air, and njpeaj, 
307 



308 



GLOSSARY. 



tereo, to keep ; because the ancients 
thought that the arteries contained only 
air.] A tube through which blood flows 
from the heart. 

A-ryt-e/noid. [Gr. apvraiva, arutaina, a 
ewer, and eiSos, eidos, form.] The name 
of a cartilage of the larynx. 

As-cend'ens. [L.J Ascending; rising. 

As-phyx'i-a. [Gr. a, a, not, and <t</>v£is, 
sphyxis, pulse.] Originally, want of 
pulse; now used for suspended respira- 
tion, or apparent death. 

As-trag'a-lus. [Gr.] The name of a bone 
of the foot. One of the tarsal bones. 

Aud-i'tion. [L. audio, to hear.] Hearing. 

Aud-it-o'ri-us. [L.] Pertaining to the or- 
gan of hearing. 

Au'ri-cle. [L. auricula, the external ear ; 
from auris, the ear.] A cavity of the 
heart. 

Ax-ii/la. [L.] The armpit. 

Ax'il-la-ry. Belonging or relating to the 
armpit. 

A-zote'. [Gr. a, a, not, and £0017, zoe, life.] 
Nitrogen. One of the constituent ele- 
ments of the atmosphere. So named be- 
cause it will not sustain life. 

Ben-zo^ic. Benzoic acid. A peculiar vege- 
table acid obtained from benzoin and 

some other balsams. 
Biceps. [L. bis, twice, and caput, a head.] 

A name applied to muscles with two 

heads at one extremity. 
Bi-cus'pids. [L. bis, two, and cuspis, a point.] 

Teeth that have two points upon their 

crown. 
Bile. [L. bilis.] A yellow, viscid fluid 

secreted by the liver. 
Bi-pen/ni-form. [L. bis, two, and penna, a 

feather.] Having fibres on each side of 

a common tendon. 
Brachial. [L. brachium.\ Belonging to 

the arm. 
Bre/vis. [L.] Brevis, short; brevior, 

shorter. 
Bronch'i-a, -m. [L.] A division of the 

trachea that passes to the lungs. 
Bronch-i/tis. [L.] An inflammation of 

the bronchia. 
Buc-ci-na/tor. [L. buccinum, a trumpet.] 

The name of a muscle of the cheek, so 

named because used in blowing wind 

instruments. 



Bur/sje Mu-c p/gA. [L. bursa, a purse, and 
mucosa, viscous.] Small sacs, containing 
a viscid fluid, situated about the joints, 
under tendons. 

C^/cum. [L.] Blind; the name given to 
the commencement of the colon. 

Cai/ci-um. [L.] The metallic basis of lime. 

Calx, Cal'cis. [L.] The heel-bone. 

Cap/il-la-ry. [L. capillus, a hair.] Re- 
sembling a hair; a small tube. 

Cap/sule. [L. capsula, a little chest.] A 
membranous bag, enclosing a part. 

Ca/pdt. [L.] The head. Caput coli, the 
head of the colon. 

Car/bon. [L. carbo, a coal.] Pure charcoal. 
An elementary combustible substance. 

Car-bon'ic. Pertaining to carbon. 

Car'm-ac. [Gr. *cap5ia, kardia, heart.] 
Relating to the heart, or upper orifice 
of the stomach. 

Car/ne-a, -je. [L. caro, carnis, flesh.] 
Fleshy. 

Ca-rot/id. [Gr. /capo?, Tcaros, lethargy.] 

. The great arteries of the neck that con- 
vey blood to the heart. The ancients 
supposed drowsiness to be seated in 
these arteries. 

Car/pus, -i. [L.] The wrist. 

Car/ti-lage. [L. cartilago.] Gristle. A 
smooth, elastic substance, softer than 
bone. 

Cau-ca^sian. One of the races of men. 

Ca/va. [L.] Hollow. Vena Cava. A name 
given to the two great veins of the body. 

Cei/lu-lar. [L. cellula, a little cell.] Com- 
posed of cells. 

Cer-e-bei/lum. [L.] The hinder and 
lower part of the brain, or the little 
brain. 

Cer/e-bro-Spi/nal. Relating to the brain 
and spine. 

Cer/e-brum. [L.] The front and large 
part of the brain. The term is some- 
times applied to the whole contents of 
the cranium. 

Cer/vi-cal. Relating to the neck. 

Cer/vix. [L.] The neck. 

Chest. [Sax.] The thorax ; the trunk of 
the body from the neck to the abdomen. 

Chlo/rine. [Gr. x^ w P°?> chloros, green.] 
Chlorine gas, so named from its color. 

Chor/da, -je. [L.] A cord. An assemblage 
of fibres. 



GLOSSARY. 



309 



Choroid. [Gr. x°P LOV -> chcnnon.'] A term 
applied to several parts of the body that 
resemble the skin. 

Chyle. [Gr. x v ^°^i chulos, juice.] A nutri- 
tive fluid, of a whitish appearance, which 
is extracted from food by the action of 
the digestive organs. 

Chyl-i-fi-ca^tion. [L. chylus, chyle, and 
facio, to make.] The process by which 
Chyle is formed. 

Chyme. [Gr. x v P-°^i chumos, juice.] A kind 
of grayish pulp formed from the food in 
' the stomach. 

Chfm-i-f-ica/tion. [L. chumos, chyme, and 
facio, to make.] The process by which 
chyme is formed. 

Cil/ia-ry. [L. cilia, eyelashes.] Belonging 
to the eyelids. 

Cin-e-ri'tiods. [L. cinus, ashes.] Having 
the color of ashes. 

ClaWi-cle. [L. clavicula, from clavis, a 
key.] The collar-bone ; so called from 
its resemblance in shape to an ancient 
key. 

Clei^do. A term applied to some muscles 
that are attached to the clavicle. 

Co-ag/u-ltjm. [L.] A coagulated mass; a 
clot of blood. 

Coc'cyx. [Gr.] An assemblage of bones 
joined to the sacrum. 

Coch'le-a. [Gr. koxAo>, Icochlo, to twist ; or 
L. cochlea, a screw.] A cavity of the ear 
resembling in form a snail-shell. 

Co'lon. [Gr. KoiXov, kolon, I arrest.] A por- 
tion of the large intestine. 

Co-lum^na, -m. [L.] A column or pillar. 

Com/mis-sure. [L. committo, I join to- 
gether.] A point of union between two 
parts. 

Com-mu'nis. [L.] A name applied to cer- 
tain muscles. 

Com-plex^us. [L. complector, to embrace.] 
The name of a muscle that embraces 
many attachments. 

Com-press/or. [L. con, together, and premo, 
pressus, to press.] A term applied to some 
muscles that compress the parts to which 
they are attached. 

Condyle. [Gr. kovSvXos, Jcondulos, a 
knuckle, a protuberance.] A promi- 
nence on the end of a bone. 

Con-junc-tf'va. [L. con, together, andjungo, 
to join.] The membrane that covers the 
anterior part of the globe of the eye. 



Cop^per. A metal of a pale red color tinged 

with yellow. 
Cor-a^coid. [Gr. icopag, Jcorax, a crow, and 

eiSo?, eidos, form.] A process of the 

scapula shaped like the beak of a crow. 
Co'ri-um. [Gr. x°P l0v i chorion, skin.] The 

true skin. 
Corn^e-a. [L. cornu, a horn.] The trans- 
parent membrane in the fore part of the 

eye. 
Cor/po-ra. [L. corpus, a body.] The name 

given to eminences or projections found 

in the brain and some other parts of the 

body. 
Cos/ta. [L. costa, a coast, siue or rib.] 

A rib. 
Crib/ri-form. [L. cribrum, a sieve, and 

forma, form.] A plate of the ethmoid 

bone, through which the olfactory nerve 

passes to the nose. 
Cricoid. [Gr. /cpiKos, Tcrihos, a ring, and 

eiSo?, eidos, form.] A name given to a 

cartilage of the larynx, from its form. 
Crystal-line. [L. crystallinus, consisting 

of crystal.] Crystalline lens, one of the 

humors of the eye. It is convex, white, 

firm and transparent. 
Cu'bi-tus, -i. [L. cubitus, the elbow.] One 

of the bones of the forearm, also called 

the ulna. 
Cu^boid. [Gr. Kvfioq, Tcubos, a cube, and 

eiSo?, etdos, form.] Having nearly the 

form of a cube. 
Cu-ne'i-form. [L. cuneus, a wedge.] The 

name of bones in the wrist and foot. 
Cus'pid. [L. cuspis, a point.] Having one 

point. 
Cc-ta^ne-ous. [L. cutis, skin.] Belonging 

to the skin. 
Cu'ti-cle. [L. cutis.] The external layer 

of the skin. 
Cu/tis Ve'ra. [L. cutis, skin, and vera, 

true.] The internal layer of the skin; 

the true skin. 

De-cus-sa/tion. [L. decutio, I divide.] A 
union in the shape of an X or cross. 

Dei/toid. [Gr. SeAra, delta, the Greek let- 
ter A, and eifios, eidos, form ] The name 
of a muscle that resembles in form the 
Greek letter A. 

Dent/al. [L. dens, tooth.] Pertaining to 
the teeth. 

De-press/or. [L.] The name of a muscle 



310 



GLOSSARY. 



that draws down the part to which it is 
attached. 

DermAhd. [Gr. 5epp.a, derma, the skin, 
and eiSos, eidos, form.] Resembling skin. 

De-scend/ens. [L. de and scando, to climb.] 
Descending, falling. 

Di'a-phragm. [Gr. 6ia</>ptvyjua, diaphragma, 
a partition.] The midriff; a muscle sepa- 
rating the chest from the abdomen. 

Di-ar-rhoe/a. [Gr. 8iappe(o, diarrheo, to flow 
through.] A morbidly frequent evacua- 
tion of the intestines. 

Di-ar-thro'sis. [Gr. 6ia, dia, through, and 
apBpovv, arthroun, to fasten by a joint.] 
An articulation which permits the bones 
to move freely on each other in every 
direction. 

Di-as/to-le. [Gr. SiaoTeAAw, diastello, to 
put asunder.] The dilatation of the 
heart and arteries when the blood enters 
them. 

Di-ges/tiox. [L. digestio.j The process of 
dissolving food in the stomach and pre- 
paring it for circulation and nourish- 
ment. 

Dig-i-to'rum. [L. digitus, a finger.] A 
term applied to certain muscles of the 
extremities. 

Dor/sal. [L. dorsum, the back.] Pertain- 
ing to the back. 

Du-o-DiA\UM. [L, duodenus, of twelve 
fingers' breadth.] The first portion of 
the small intestine. 

Du'ra Master. [L. durus, hard, and 
mater, mother.] The outermost mem- 
brane of the brain. 

Dys'en-ter-t. [Gr. 8vs, dus, bad, and 
evTepta, enteria, intestines.] A discharge 
of blood and mucus from the intestines 
attended with tenesmus. 

Drs-PEP/si-A. [Gr. Sus, dus, bad, and neirrio, 
pepto, to digest.] Indigestion, or diffi- 
culty of digestion. 

En-am/el. [Fr.] The smooth, hard sub- 
stance which covers the crown or visible 
part of a tooth. 

En-dos-mo'sis. [Gr. evtW, endon, within, 
and 0007x0s, osmos, to push.] The trans- 
mission of fluids through membranes, 
inward. 

E-penAdy-ma. [Gr.] The membrane which 
lines the ventricles of the brain. 

Ep-i-derm'is. [Gr. en-i, epi, upon, and 



Sepp.a, derma, the skin.] The superficial 
layer of the skin. 

Ep-i-glotAiis. [Gr. eiri, epi, upon, and 
yAxoTTa, glotta, the tongue.] One of the 
cartilages of the glottis. 

Eth'moid. [Gr. r)9p.o<;, ethmos, a sieve, and 
eiSos, eidos, a form.] A bone of the skull. 

Eu-sta'chi-an Tube. A channel from the 
fauces to the middle ear, named from 
Eustachius, who first described it. 

Ex/cre-ment. [L. excerno, to separate.] 
Matter excreted and ejected ; alvine dis- 
charges. 

Ex'ore-to-ry. A little duct or vessel, des- 
tined to receive secreted fluids and to 
excrete or discharge them ; also a se- 
cretory vessel. 

Ex-h aslant. [L. exhalo, to send forth 
vapor.] Having the quality of exhaling 
or evaporating. 

Ex-tens/or. [L.] A name applied to a 
muscle that serves to extend any part 
of the body ; opposed to Flexor. 

Fascial. [L. fades, face.] Pertaining to 
the face. 

Falx. [L. falx, a scythe.] A process of 
the dura mater shaped like a scythe. 

Fas'ci-a. [L. fascia, a band.] A tendinous 
expansion or aponeurosis. 

Fas-cic/u-lus, -li. [L. fascis, a bundle.] 
A little bundle. 

Faux, -ces. [L.] The top of the throat. 

Fem/o-ral. Pertaining to the femur. 

Fe/jviur. [L.] The thigh-bone. 

Fe-nes'tra, -um. [L. fenestra, a window.] 
A term applied to some openings into 
the internal ear. 

Fi/bre. [L. Jibra.] An organic filament or 
thread which enters into the composition 
of every animal and vegetable texture. 

Fibrin. A peculiar organic substance 
found in animals and vegetables ; it is a 
solid substance, tough, elastic and com- 
posed of thready fibres. 

Fi/bro-Car/ti-lage. An organic tissue, par- 
taking of the nature of fibrous tissue and 
that of cartilage. 

FibAj-la. [L., a clasp.] The outer and 
lesser bone of the leg. 

Fii/.\-ment. [L. filamenta, threads.] A fine 
thread, of which flesh, nerves, skin, etc., 
are composed. 

Flexion. [L.flectio.] The act of bending. 



GLOSSARY. 



311 



Foi/li-cle. [L. folliculus, a small bag.] 

A gland ; a little bag in animal bodies. 
Fore/arm. The part of the upper extremity 

between the elbow and hand. 
Fos^sa. [L., a ditch.] A cavity in a bone, 

with a large aperture. 
Fr^/num. [L., a bridle.] Frsenum linguse, 

the bridle of the tongue. 
Function. [L. fungor, to perform.] The 

action of an organ or system of organs. 
Fun'gi-form. [L. fungus and forma.] 

Having terminations like the head of a 
* fungus, or a mushroom. 

Gan^gli-on, -a. [Gr.] An enlargement in 
the course of a nerve. 

Gas'tric. [Gr. ya<rrr\p, gaster, the stomach.] 
Belonging to the stomach. 

G AS-TROONEf mi-us. [Gr. ya<m}p, gaster, the 
stomach, and Kvrjp.7}, Jcneme, the leg.] 
The name of large muscles of the leg. 

Gei/a-tin. [L. gelo, to congeal.] A con- 
crete animal substance, transparent and 
soluble in water. 

GiNG/LY-FORM. [Gr. yt,yy\vno<;, ginglymos, 
a knife-like joint, and eiSos, eidos, a 
form.] An articulation that only admits 
of motion in two directions. 

Glenoid. [Gr. y\r\vr), glene, a cavity.] A 
term applied to some articulate cavities 
of bones. 

Glos'sa. [Gr.] The tongue. Names com- 
pounded with this word are applied to 
muscles of the tongue. 

Glos/so-Pha-ryn/gi-al. Relating to the 
tongue and pharynx. 

Glot/tis. [Gr.] The narrow opening at 
the upper part of the larynx. 

Glu'te-us. [Gr.] A name given to muscles 
of the hip. 

Gom-pho'sis. [Gr. yoix<f)ovv, gomphoun, a 
nail.] The immovable articulation of the 
teeth with the jaw-bone, like a nail in a 
board. 

Hem'or-rhage. [Gr. aip.a, haima, blood, 
and priyvvoi, regnuo, to burst.] A dis- 
charge of blood from an artery or brain. 

His-toi/o-gy. [Gr. io-ros, histos, tissue, and 
Aoyo?, logos, discourse.] A description 
of the minute structure of the bod} 7 . 

Hu'mer-tjs. [L.] The bone of the arm. 

Hy'a-loid. [Gr.] A transparent mem- 
brane of the eve. 



Hy^dro-gen. [Gr. vScop, hydor, water, and 

yevvaoi, gennao, to generate.] A gas 

which constitutes one of the elements 

of water. 
Hy'gi-ene. [Gr. vyieivov, hugieinon, health.] 

The part of medicine which treats of the 

preservation of health. 
Hy^oid. [Gr. v and eiSos, eidos, shape.] 

A bone of the tongue resembling the 

Greek letter Upsilon in shape. 
Hy^po-glos'sal. Under the tongue. The 

name of a nerve of the tongue. 

Il'e-um. [Gr. etAto, eilo, to wind.] A por- 
tion of the small intestines. 

Ii/i-um. The haunch-bone. 

In-ci^sor. [L. incidn, to cut.] A front 
tooth that cuts or divides. 

In/dex. [L. indico, to show.] The fore- 
finger; the pointing finger. 

In-nom-i-na/ta. [L. in, not, and nomen, 
name.] Parts which have no proper name. 

In-os/cu-late. [L. in, and osculatus, from 
osculor, to kiss.] To unite, as two ves- 
sels at their extremities. 

In^ter. [L.] Between. 

In-ter-cost'al. [L. inter, between, and 
costa, a rib.] Between the ribs. 

In-ter-no'di-i. [L. inter, between, and 
nodus, knot.] A term applied to some 
muscles of the forearm. 

In-ter-stiAtial. [L. inter, between, and 
sto, to stand.] Pertaining to or contain- 
ing interstices. 

In-tes/tines. [L. intus, within.] The canal 
that extends from the stomach to the 
anus. 

I/ris. JL., the rainbow.] The colored circle 
that surrounds the pupil of the eye. 

Fvo-ry. A hard, solid, fine-grained sub 
stance of a fine white color; the tusk of 
an elephant. 

Je-j.u'num. [L., empty.] A portion of the 
small intestine. 

Ju^gu-lar. [L. jugulum, the neck.] Re- 
lating to the throat. The great veins 
of the neck. 

La/bi-um, La^bi-i. [L.] The lips. 

Lab/y-rinth. [Gr.J The internal ear. so 
named from its many windings. 

Lach^ry-mal. [L. lachryma, a tear.] Per- 
taining to tears. 



312 



GLOSSARY. 



Lac'te-al. [L. lac, milk.] A small vessel 
or tube of animal bodies for conveying 
chyle from the intestine to the thoracic 
duct. 

Lam/i-na, -m. [L.] A plate or thin coat 
tying over another. 

Lar/ynx. [Gr. \apvy£, larunx.] The upper 
part of the windpipe. 

Lar-yn-gp*tis. Inflammation of the larynx. 

La-tis'si-mus, -mi. [L., superlative of latus, 
broad.] A term applied to some muscles. 

Le-va'tor. [L. levo, to raise.] A name ap- 
plied to a muscle that raises some part. 

Lig'a-ment. [L. ligo, to bind.] A strong, 
compact substance serving to bind one 
bone to au other. 

Lin'e-a, -m. [L.] A line. 

Lin'gua, -m. [L,] A tongue. 

Liv/er. The name of one of the abdominal 
organs, the largest gland in the system. 
It is situated below the diaphragm, and 
secretes the bile. 

Lobe. A round projecting part of an organ. 

Lon'gus, Lon'gi-or. [L., long, longer.] A 
term applied to several muscles. 

Lum^bar. [L. lumbus, the loins.] Pertain- 
ing to the loins. 

Lymph. [L. lymplxa, water.] A colorless 
fluid in animal bodies, and contained in 
vessels called lymphatics. 

Lym-phat^ic. A vessel of animal bodies that 
contains or conveys lymph. 

Mag-neAsi-um. The metallic base of mag- 
nesia. 

Mag/nus, -na, -num. [L. great.] A term 
applied to certain muscles. 

Ma/jor. [L., greater.] Greater in extent 
or quantity. 

M an'ga-nese. A metal of a whitish gray 
color. 

Mar/row. [Sax.] A soft, oleaginous sub- 
stance contained in the cavities of bones. 

Mas-setter. [Gr. fiaa-a-aoixca, massaomai, 
to chew.] The name of a muscle of the 
face. 

Mas'ti-cate, Mas-ti-ca'tion. [L. mastico.] 
To chew; the act of chewing. 

Mastoid. [Gr. fxacrros, mastos, breast, and 
etfiov, eidos, form.] The name of a pro- 
cess of the temporal bone behind the ear. 

Mas toid'e-us. A name applied to muscles 
that are attached to the mastoid process. 

Max-ii/la. [L.] The jaw-bone. 



Max'i-mus, -um. [L., superlative of mag- 
nus, great.] A term applied to several 
muscles. 

Me-aAtus. [L. meo, to go.] A passage or 
channel. 

Me-m-as-ti^num. A membrane that sepa- 
rates the chest into two parts. 

Me/di-um, -a. [L.] The space or substance 
through which a body passes to any 
point. 

Med^ul-la-ry. [L. medulla, marrow.] Per- 
taining to marrow. 

Me-dui/la Ob-lon-ga/ta. Commencement 
of the spinal cord. 

Me-dui/la Spi-xa/lis. The spinal cord. 

Mem/bra-na. A membrane ; a thin, white, 
flexible skin formed by fibres interwoven 
like network. 

Mes/en-TER-Y. [Gr. /u.e<xo9, mesos, the middle, 
and evrepov, enteron, the intestine.] The 
membrane in the middle of the intes- 
tines by which they are attached to the 
spine. 

Met-a-car/pus. [Gr. fxera, meta, after, and 
Kap-rros, karpos, wrist.] The part of the 
hand between the wrist and fingers. 

Met-a-tar/sus. [Gr. /xeTa, meta, after, and 
Tapaos, tar sos, the tarsus.] The instep. 
A term applied to seven bones of the 
foot. 

Mid/riff. [Sax. mid, and hrife, the belly.] 
See Diaphragm. 

Min'i-mus. [L.] The smallest. A term 
applied to several muscles. 

Mi^nor. [L.] Less, smaller. A term ap- 
plied to several muscles. 

Mistral. [L. mitra, a mitre.J The name 
of the valves on the left side of the heart. 

Mo-di'o-lus. [L. modus, a measure.] A 
cone in the cochlea around which the 
membranes wind. 

Mo'lar. [L. mola, a mill.] The name of 
some of the large teeth. 

Moi/lis. [L.] Soft. 

Mo/tor, -es. [L. moveo, to move.] A mover. 
A term applied to certain nerves. 

Mu'cous. Pertaining to mucus. 

Mu'cus. A viscid fluid secreted by the 
mucous membrane, which it serves to 
moisten and defend. 

Mus'cle. A bundle of fibres enclosed in a 
sheath. 

My-o'des. A term applied to certain 
muscles of the neck. 



GLOSS AKY. 



313 



My-o-lem'ma. [Gr. javs, mus, a muscle, and 
Ae/x/uta, lemma, to receive.] The invest- 
ing membrane of a fibre. 

MY-oi/o-Gr. [Gr. /w.vs, mus, a muscle, and 
Aoyos, logos, a discourse.] A description 
of the muscles. 

Na'sal. Relating to the nose. 

Nerve. An organ of sensation and motion 

in animals. 
Nerv'ous Cen/tre. A collection of gray 

nervous matter, which receives impres- 
sions and originates the nervous im- 



Neu-ri-lem'a. [Gr. vevpov, neuron, a nerre, 
and XcfjLfjLa, lemma, a sheath.] The sheath 
or covering of a nerve. 

Neu-roi/o-gy. [Gr. vevpov, neuron, a nerve, 
and Aoyo?, logos, a discourse.] A descrip- 
tion of the nerves of the body. 

Ni'tro-gen. That element of the air which 
is called azote. 

Nu'cle-us. [L. nux, a nut.] The central 
part of any body, or that about which 
matter is collected. 

Nu-tri^tion. The art or process of pro- 
moting the growth or repairing the 
waste of the system. 

Oc/ci-put. [L. ob, and caput, the head.] 

The hinder part of the head. 
Oc'u-lus, -i. [L.] The eye. 
(E-soph/a-gus. [Gr. otto, aid, to carry, and 

<payat, phago, to eat.] The name of the 

passage through which the food passes 

from the mouth to the stomach. 
O-lec/ra-non. [Gr. utkeve, olene, the cubit, 

and upavov, kranon, the head.] The 

elbow ; the head of the ulna. 
(Vle-in. An oily substance which is fluid 

at ordinary temperatures. 
Ol-factA>ry. [L. oleo, to smell, and facio, 

to make.] Pertaining to smelling. 
O-men/tum. [L.] The caul. 
O^mo. [Gr. co/ao?, omos, the shoulder.] 

The name of muscles attached to the 

shoulder. 
Oph-thai/mic. [Gr. (HpOaXfios, ophthalmos, 

the eye.] Belonging to the eye. 
Op-po^nens. That which acts in opposition 

to something. The name of two muscles 

of the hand. 
Op'ti-cus, Op'tic. [Gr. o7TTo/u.at, optomai, 

to see.] Relating to the eye. 
27 



Or-bic'u-lar. [L. orbis, a circle.] Circular. 

Or/gan. A part of the system destined to 
exercise some particular function. 

Or/i-gin. Commencement; source. 

Os. [L.] A bone; the mouth of anything. 

Os'ma-zome. [Gr. 007x17, osme, smell, and 
^toju.09, zomos, broth.] A principle ob- 
tained from animal fibre which gives the 
peculiar taste to broth. 

Os'se-ous. Pertaining to bones. 

Os^si-fy. [L. ossa, bones, and facio, to 
make.] To convert into bone. 

OsAte-ine. [Gr. ocrreov, osteon, a bone.] 
The albuminous ingredient of the bones. 

Os-te-oi/o-gy. [Gr. oareov, osteon, a bone, 
and A0705, logos, a discourse.] The part 
of anatomy which treats of bones. 

O-va'le. [L.J The shape of an egg. 

Ox-ai/ic. Pertaining to sorrel. Oxalic acid 
is the acid of sorrel. It is composed of 
two equivalents of carbon and three of 
oxygen. 

Ox'y-gen. A permanently elastic fluid, in- 
visible and inodorous. One of the com- 
ponents of atmospheric air. 

Pa-la/tum. [L.J The palate; the roof of 
the mouth. 

Pal-pe-bra'rum. [L. palpebra, the eyelid.] 
Of the eyelids. 

Pai/mar. [L.palma, the palm.] Belong- 
ing to the hand. 

Pal-ma^ris. A term applied to some muscles 
attached to the palm of the hand. 

PanVcre-as. [Gr. irav, pan, all, and Kpeas, 
kreas, flesh.J The name of one of the 
digestive organs. 

Pan-CRE-a/tin. The albuminous ingredient 
of the pancreas. 

Pa-pii/la, -m. [L.] Small conical promi- 
nences. 

Pa-ral/y-sis. Abolition of function, whether 
of intellect, sensation or motion. 

Pa-ren^chy-ma. [Gr. napeyx^oi, parengcheo, 
to pour through.] The substance con- 
tained between the blood-vessels of an 
organ. 

Pa-ri^e-tal. [L. paries, a wall.] A bone 
of the skull. 

Pa-rot'id. [Gr. irapa, para, near, and 
o>to?, otos, the gen. of ovs, ous, ear, the 
ear.] The name of the largest salivary 
gland. 

Pa-tei/la, -m. [L.] The knee-pan. 



314 



GLOSSARY. 



Pa-thet'i-cus, -ci. [Gr. iraOos, pathos, 
passion.] The name of the fourth pair 
of nerves. 

Pec'to-ral. [L.] Pertaining to the chest. 

Pe/dis. [L., gen. of pes, the foot.] Of the 
foot. 

Pei/i-tongs. A term applied to masses 
of fat. 

Pei/li-cle. [L., dim. of pellus, the skin.] 
A thin skin or film. 

Pei/vis. [L.] The basin formed by the 
large bones at the lower part of the ab- 
domen. 

Pen'ni-form. [L. penna, a feather.] Hav- 
ing the form of a feather or quill. 

Pep'sin. [Gr. 7re7TTu>, pepto, to cook.] An 
ingredient of the gastric juice, which 
acts as a ferment in the digestion of the 
food. 

Per-i-car/di-um. [Gr. 7T€pi, peri, around, 
and Kap8ia, Jcardia, the heart.] A mem- 
brane that encloses the heart. 

Per-i-CHON^dri-um. [Gr. nept,,peri, around, 
and x ov &P°s> chondros, cartilage.] A 
membrane that invests cartilage. 

Per-i-cra'ni-um. [Gr. Trept, peri, around, 
and KpavLov, Tcranion, the cranium.] A 
membrane that invests the skull. 

Per-i-mys/i-um. [Gr. 7rept, peri, around, 
and p.v5, mus, a muscle.] The investing 
membrane of a muscle. 

Per-i-stai/tic. [Gr. 7repio-TeAAa>, peristello, 
to involve.] A movement like the crawl- 
ing of a worm. 

Per-i-to-ne^um. [Gr. 7repi, peri, around, 
and tsivclv, teinein, to stretch.] A thin, 
serous membrane investing the internal 
surface of the abdomen. 

Per/ma-nent. Durable; lasting. v 

Per-spi-ra/tion. [L. per, through, and 
spiro, to breathe.] The excretion from 
the skin. 

Phai/anx, -ges. [Gr. <f>a\ay£, phalanx, an 
army.] Three rows of small bones form- 
ing the fingers or toes. 

Pha-lan^gi-al. Belonging to the fingers 
or toes. 

Pha-ryn^ge-al. Relating to the pharynx. 

Phar^ynx. [Gr. <f>apvyg, pharunx.] The 
upper part of the oesophagus. 

Phos'phor-us. [Gr. <fxa<;, phos, the light, 
and <£epw, phero, to bear.] A combustible 
substance, of a yellowish color, semi- 
transparent, resembling wax. 



Phren'ic. [Gr. <f>pwv, phren, the mind.] 
Belonging to the diaphragm. 

Phys-i-oi/o-gy. [Gr. 0v<ris, phusis, nature, 
and Aoyo?, logos, a discourse.] The science 
of the functions of the organs of animals 
and plants. 

Pi^a Master. [L., good mother.] The 
name of one of the membranes of the 
brain. 

Pig-men'tum Ni'grum. [L.] Black paint; 
a preparation of colors. 

Pin'na. [L., a wing.] A part of the ex- 
ternal ear. 

Pla-tys/ma. [Gr. ir\arv<;, platus, broad.] 
A muscle of the neck. 

Pleu'ra, -m. [Gr. nXevpa, pleura, the side.] 
A thin membrane that covers the inside 
of the thorax, and also forms the exterior 
coat of the lungs. 

Pleu'ral. Relating to the pleura. 

Plex'us. [L. plecto, to weave together.] 
Any union of nerves, vessels or fibres, in 
the form of network. 

Pneu-mo-gas'tric. [Gr. nvevfxoyv, pneumon, 
the lungs, and yaarrfp, gaster, the stom- 
ach.] Belonging to both the stomach 
and lungs. 

Pneu-mo-noi/o-gy. [Gr. nvevfuav, pneumon, 
the lungs, and A0705, logos, a discourse.] 
A description of the lungs. 

Poi/lt-cis. [L.] A term applied to muscles 
attached to the fingers and toes. 

Pons. [L.] A bridge. Pons varolii, a part 
of the brain formed by the union of the 
crura cerebri and cerebelli. 

Pop-lit-e/al. [L, poples, the ham.] Per- 
taining to the ham or knee-joint. A 
name given to various parts. 

Pos'ti-cus. [L.] Behind; posterior. A 
term applied to certain muscles. 

Por/ti-o Du^ra. [L., hard portion.] The 
facial nerve ; eighth pair. 

Por/ti-o Moi/lis. [L., soft portion.] The 
auditory nerve; seventh pair. 

Po-tas'si-um. [L.J The metallic basis of 
pure potash. 

Pro-bos'cis. [Gr. npo, pro, before, and 
fioo-K0i, bosko, to feed.] The snout or 
trunk of an elephant or other animal. 

Proc/ess. A prominence or projection. 

Pro-na'tor. [L. pronus, turned down- 
ward.] The muscle of the forearm that 
moves the palm of the hand down- 
ward. 



GLOSS AEY. 



315 



Pro-to'plasm. [Gr. irp(oTo^,.protos, first, 
and irXao-fJLa, plasma, formed.] The for- 
mal basis of all living bodies. 

Psoras. [Gr. xf/ocu, psoai, the loins.] The 
name of two muscles of the leg. 

PUL-MON^IC, "\ 

Pui/mo-na-ry, > [L. pulmo, the lungs.] 

PUL-MO-NA^LIS. J 

Belonging or relating to the lungs. 

Pu'pil. A little aperture in the centre of 
the iris, through which the rays of light 
pass to the retina. 

Py-lor/ic. Pertaining to the pylorus. 

Py-lo'rus. [Gr. nvKaipos, puloros, a gate- 
keeper.] The lower orifice of the stom- 
ach, with which the duodenum connects. 

Ka'di-us. [L., a ray, a spoke of a Wheel.] 
The name of one of the bones of the 
forearm. 

Ra/di-ate. Having lines or fibres that 
diverge from a point. 

Rasmus. [L.] A branch. A term applied 
to the projections of bones. 

Rec-re-men-tj/tial. [L. re, again, and 
cerno, to secrete.] Consisting of super- 
fluous matter separated from that which 
is valuable. 

Rec'tum. The third and last portion of the 
intestines. 

Rec/tus, -i. [L.] Straight; erect. A term 
applied to several muscles. 

Reg/i-men. [L. rego, to govern.] The sys- 
tematic regulation of the food and drink. 

Re-sid^u-um. [L.] Waste matter. The 
faeces. 

Res-pi-ra/tion. [L. re, again, and spiro, 
to breathe.] The act of breathing. In- 
spiring air into the lungs and expelling 
it again. 

Re-spp'ra-to-rf. Pertaining to respiration ; 
serving for respiration. 

Ret/i-na. [L. rete, a net.] The essential 
organ of sight. One of the coats of the 
eye, formed by the expansion of the 
optic nerve. 

Ro-tun^dum, -a. [L.] Round ; circular. 

Ru'ga, -je. [L.] A wrinkle ; a fold. 

Sac^cu-lus. [L., dim. of saccus, a bag.] A 

little sac. 
Sa^cral. Pertaining to the sacrum. 
Sa/crum. [L., sacred.] The bone which 

forms the posterior part of the pelvis, 



and is a continuation of the spinal 
column. 

Sa-li/va. [L.] The fluid which is secreted 
by the salivary glands, which moistens 
the food and mouth. 

San/guin-e-ous. [L. sanguis, the blood.] 
Bloody ; abounding with blood ; ple- 
thoric. 

Sar-to/ri-us. [L. sartor, a tailor.] A term 
applied to a muscle of the thigh. 

Sca/la, -m. [L., a ladder.] Cavities of the 
cochlea. 

Sca-le^nus. [Gr. <rica\r)vo<;, skalenos, un- 
equal.] A term applied to some muscles 
of the neck. 

ScaphAhd. [Gr. c/ca^Tj, sTcaphe, a little 
boat.] The name applied to one of the 
wrist-bones. 

Scap/u-la. [L.] The shoulder-blade. 

Scap/u-lar. Relating to the scapula. 

Sci-at/ic. [Gr., pertaining to the loins.] 
The name of the large nerve of the loins 
and leg. 

Scle-rot/ic. [Gr. aicXripos, skier os, hard.] 
A membrane of the eye. 

Se-ba/ceous. [L. sebum, tallow.] Pertain- 
ing to fat ; unctuous matter. 

Se-cre/tion. The act of producing from 
the blood substances different from the 
blood itself, as bile, saliva; the matter 
secreted, as mucus, bile, etc. 

Se-cre'to-ry. Performing the oflBce of se- 
cretion. 

Se-cun^dus. Second. A term applied to 
certain muscles. 

Sem-i-cir/cu-lar. Having the form of a 
half circle. The name of a part of the 
ear. 

Sem-i-lu'nar Valves. [L. semi, half, and 
luna, the moon.] Name of the three 
festooned valves of the heart, at the 
entrance of the great arteries. 

Sem-i-ten-di-no^sus. [L. semi, half, and 
tendo, a tendon.] The name of a muscle. 

SepAtum. [L.] A membrane that divides 
two cavities from each other. 

Se/rous. Thin; watery. Pertaining to 
serum. 

Se/rum. [L.] The thin, transparent part 
of blood. 

Ser-ra/tus. [L. serro, to saw.] A term 
applied to some muscles of the trunk. 

Sigmoid. [Gr.] Resembling the Greek ?, 
Sigma. 



316 



GLOSSARY. 



Si-Ltfci-UM. A term applied to one of the 

earths. 
Si'nus. [L., a bay.] A cavity, the interior 

of which is more expanded than the 

entrance. 
Skei/e-ton. [Gr. <™eAAa>, skello, to dry.] 

The aggregate of the hard parts of the 

body ; the bones. 
Sofm-UM. The metallic base of soda. 
Sphenoid. [Gr. <t<$>t)v, sphen, a wedge, and 

eiSos, exdos, likeness.] A bone at the 

base of the skull. 
Sphincter. [Gr. <r<f>iyy<a, sphingo, to re- 
strict.] A muscle that contracts or shuts 

an orifice. 
Spinal Cord. A prolongation of the brain. 
Spine. A thorn. The vertebral column ; 

back-bone. 
Splanch-noi/o-gy. [Gr. <nr\ayxvov, splanch- 

non, the bowels, and Aoyos, logos, a dis-^ 

course.] A description of the internal 

parts of the body. 
Spleen. The milt. It is situated in the 

abdomen and attached to the stomach. 
Sple'ni-us. The name of a muscle of the 

neck. 
Squa/mose. [L.] Scaly. 
Stages. The name of one of the small 

boues of the ear. 
Ste/ar-in. [Gr. areap, stear, suet.] One of 

the proximate principles of animal fat, 

which is solid at ordinary temperatures. 
Stee/num. The breast-bone. 
Stom'ach. The principal organ of the 

digestive apparatus. 
Stra/tcm. [L. sterno, to spread.] A bed ; 

a layer. 
Styloid. [L. stylus, a pencil.] An epithet 

applied to processes that resemble a 

style, a pen. 
Sub-cla^vi-an. [L. sub, under, and clavis, 

a key.] Situated under the clavicle. 
Sub-lin/gual. [L. sub, under, and lingua, 

the tongue.] Situated under the tongue. 
Sub-max/il-la-ry. [L. sub, under, and 

maxilla, the jaw-bone.] Located under 

the jaw. 
Sui/phur. A simple mineral substance, 

of a yellow color, brittle, insoluble in 

water, but fusible by heat. 
Su-pi-na'tor. [L.] A muscle that turns 

the palm of the hand upward. 
Sut/ure. [L. suo, to sew.] The seam or 

joint that unites the bones of the skull. 



Syn-ar-thro/sis. [Gr. aw, sun, with, and 
ap9pov, arthron, a joint.] An immovable 
articulation. 

Syn-o^vi-a. [Gr. aw, sun, with, and wov, 
oon, an egg.] The fluid secreted into the 
cavities of joints for the purpose of lubri- 
cating them. 

Sys'tem. An assemblage of organs, com- 
posed of the same tissues and intended 
for the same functions. 

Sys-tem'ic. Belonging to the general sys- 
tem. 

Sys'to-le. [Gr. avareWoj, sustello, to con- 
tract.] The contraction of the heart and 
arteries for expelling the blood and 
carrying on the circulation. 

Tar/sus. [L.] The posterior part of the 

foot. 
Tendon. [Gr. reivm, teino, to stretch.] A 

hard, insensible cord, or bundle of fibres, 

by which a muscle is attached to a bone. 
Tens'or. A muscle that extends a part. 
Ten-tac'u-la, -m. [L. tento t to seize.] A 

filiform process or organ on the bodies 

of various animals. 
Ten-to/ri-um. [L. tendo, to stretch.] A 

process of the dura mater which lies be- 
tween the cerebrum and cerebellum, 
Te'res. [L. teres t round.] An epithet given 

to many organs, the fibres of which are 

collected in small bundles. 
Tho'rax. [Gr.] That part of the skeleton 

that composes the bones of the chest. 

The cavity of the chest. 
Tho-rac/ic. Relating to the chest. 
Thy/roid. [Gr. Ovpeos, tliureos, a shield.] 

Resembling a shield. A cartilage of the 

larynx. 
Tip/i-a. [L., a flute.] The large bone of 

the leg. 
Tis/sue. The texture or organization of 

parts. 
Ton'sil. [L.] A glandular body in the 

throat or fauces. 
Tra^che-a. [Gr. rpa^vs, trachus, rough.] 

The windpipe. 
Trans-verse/, Trans-ver-sa^lis. Lying in 

a cross direction. 
Tra-pe'zi-us. The name of a muscle, so 

called from its form. 
Triceps. [L. tres, three, and caput, head.] 

Three. A name given to muscles that 

have three attachments at one extremity. 



GLOSSARY. 



317 



Tri-cus^pid. [L. tres, three, and cuspis, 
point.] The triangular valves in the 
right side of the heart. 

Trit/u-rat-ing. Grinding to a powder. 

Troch/le-a. [Gr. rpoxaAta, irochalia, a 
pulley.] A pulley-like cartilage, over 
which the tendon of a muscle of the eye 



Trunk. The principal part of the body, to 
which the limbs are articulated. 

Tu'ber-cle. [L. tuber, a bunch.] A pimple, 

swelling or tumor on animal bodies. 
' Tym'pan-um. [L.] The middle ear. 

Ui/na. [L.] A bone of the fore-arm. 

Ui/nar, Ul-na/ris. Relating to the ulna. 

U-re^ter. [Gr. ovpetv, ourein, to conduct 
water.] The excretory duct of the kid- 
neys. 

U^ric. [Gr. ovpov. ouron, urine.] An acid 
contained in urine and in gouty con- 
cretions. 

U-ve/a. [L. uva, a grape.] Resembling 
grapes. A thin membrane of the eye. 

U'vu-LA. A soft body suspended from the 
palate, near the aperture of the nostrils, 
over the glottis. 

Vac'cine Vi'rus. [L. vacca, a cow, virus, 
poison.] Pertaining to cows; derived 
from cows. 

Valve. Any membrane, or-doubling of 
any membrane, which prevents fluids 
from flowing back in the vessels and 
canals of the animal body. 

Vas/cu-lar. [L. vasculum, a vessel.] Per- 
taining to vessels; abounding in ves- 
sels. 

27* 



Vas/tus. [L.] Great, vast. Applied to 

some large muscles. 
Veins. Vessels that convey blood to the 

heart. 
Ve'nous. Pertaining to veins. 
Ven'tri-cle. [L. venter, the stomach.] A 

small cavity of the animal body. 
Ver-mk/u-lar. [L. vermiculus, a little 

worm.] Resembling the motions of a 

worm. 
Verm-i-form^is. [L. vermis, a worm, and 

forma, form.] Having the form and 

shape of a worm. 
Vert'e-bra, -m. [L. verto, to turn.] A joint 

of the spinal column. 
Vert'e-bral. Pertaining to the joints of 

the spinal column. 
Ves/i-cle. [L. vesica, a bladder.] A little 

bladder, or a portion of the cuticle sepa- 
rated from the cutis vena and filled with 

serum. 
Ves^ti-bule. [L.] A porch of a house. 

A cavity belonging to the ear. 
Vii/li. [L.] Fine, small fibres. 
Vi'rus. [L., poison.] Foul matter of an 

ulcer; poison. 
Vi^tal. [L. vita, life.] Pertaining to life. 
Vit're-ous. [L. vitrum, glass.] Belonging 

to glass. A humor of the eye. 
Vo'lar. [L. vola, the hollow of the hand 

or foot.] Belonging to the palm of the 

hand. 
Vo'mer. [L., a ploughshare.] One of the 

bones of the nose. 

Ztg-o-mat'i-cus. [Gr. £vyo9, zugos, a yoke.] 
A term applied to some muscles of the 
face, from their attachment. 



INDEX. 



Absorbents, Anatomy of, 138. 

Histology of, 141. 

Chemistry of, 143. 

Physiology of, 144. 

Hygiene of, 146. 
Absorption, 138. 
Acids, Cerebric, 33. 

Cholic, 33. 

Lactic, 32. 

Uric, 33. 
Air, 197, 297, 303. 
Air-Cells, 187. 
Albumen, 31. 
Albuminoids, 31. 
Albuminose, 31. 
Angiology, Comparative, 172. 
Aponeurosis, 74. 
Aorta, Thoracic, 152. 

Abdominal, 153. 
Arteries, 150-159. 
Articulata, Definition of, 67. 
Assimilation, 176. 
Auricle, of the Heart, 150. 
Asphyxia, from Drowning, 205. 

from Electricity, 205. 

from Hanging, 205. 

from Carbonic Acid Gas, 20^ 
Azote, 31. 

Bathing, 290, 294. 
Beds, Making of, 302. 
Bile, 118. 
Bilverdin, 33. 
Blood, 149, 161. 
Blood- Vessels, 81, 149. 
Bones, Anatomy of, 36. 

Histology of, 49. 

Chemistry of, 55. 

Physiology of, 55. 

Hygiene of, 60. 

Fractured, 64. 
Brain, 218. 
Bronchi, 184-187. 



Burns and Scalds, 297. 
Burs^; Mucosa, 53. 

Canaliculi, 50. 
Canal of Havers, 50. 
Capillaries, 22, 151, 160. 
Carbon, 34. 
Cartilage, 53, 59. 
Cartilagen, 32. 
Cells, Definition of, 15. 
Cellular Tissue, 18. 
Cerebellum, 213. 
Cerebro-Spinal Axis, 212. 
Cerebrum, 215. 
Chest, Compression of, 203. 
Chilblains, 298. 
Chlorine, 34. 
Chondrigen, 32. 
Chtle, 120. 
Chyme, 121. 
Circulatory Organs, 150. 

Histology of, 156. 

Physiology of, 162. 

Hygiene of, 168. 
Clothing, 291. 
Cochlea, 271. 

Commissures of the Brain, 212. 
Corns, Treatment of, 298. 
Corpora Amylacea, 34. 
Corpus Callosum, 216. 
Cruorin, 32. 
Crystalline Lens, 266. 
Cutis Anserina, 279. 
Cuticle, 276. 
Cutis Vera, 276. 

Definitions, General, 13. 

Dermis, 276. 

Digestive Organs, Anatomy of, 103. 

Histology of, 110. 

Chemistry of, 116. 

Physiology of, 120. 

Hygiene of, 120. 

319 



320 



INDEX. 



Distinctions between the Mineral, Vege- 
table and Animal Kingdoms, 11. 
between Organized and Unorganized 

Bodies, 12. 
between Animals and Plants, 12. 
Drinks, 127. 
Drowned Persons, Treatment of, 205. 

Ear, Bones of, 273. 

External, 274. 

Middle, 272. 

Internal, 270. 

Physiology of, 285 
Elastin, 33. 
Endocardium, 157. 
Epidermis, 274. 
Epiglottis, 184. 
Epithelium, 25. 
Eustachian Tube, 273. 
Excretion, 179. 
Eye, 264, 282. 

Protecting Organs of, 268. 

Face, Bones of, 38. 
Fascia, 74. 
Fasciculi, 79. 
Fats, 33. 
Fenestra, 272. 
Fibre, 22. 
Fibrin, 31. 
Fibro-Cartilage, 20. 
Food, Quantity of, 123. 

Quality of, 125. 

Manner of taking, 127. 

Conditions when taking, 128. 
Frost-Bite, Treatment of, 298. 

Ganglia, 210. 
Ganglionic Corpuscle, 24. 
Gastric Juice, 117. 
Gelatin, 32. 
Glands, Lachrymal, 269. 

Lymphatic, 140-142. 

Oil, 279, 287. 

Perspiratory, 279, 287. 

Salivary, 107. 
Globulin, 32. 
Glucose, 33. 
Glycerine, 33. 

Hjbmatin, 32. 
Hair-Follicles, 278. 
Heart, 150. 

Auricles of, 150, 157. 

Ventricles of, 150, 158. 



Hearing^ Sense of, 270. 

Hemorrhage, Means of Arresting, 169. 

Hydrogen, 34. 

Inosit, 33. 
Intestines, 108-114. 
Intestinal Juice, 119. 
Iris, 265. 

Joints, 47. 

Physiology of, 59. 

Keratin, 33. 
Kidneys, 180. 

Labyrinth, 270. 
Lachrymal Apparatus, 268. 
Lacteals, 137. 
Lactin, 33. 
Lacuna, 50, 59. 
Larynx, 183-186, 195. 
Ligament, 41, 54. 
Light, 297. 
Liver, 109-114. 
Lungs, 185, 187. 
Lymph, 137-143. 
Lymphatics, 140, 144. 

Margarin, 33. 

Meatus Auditorius, 274. 

Medulla, 52. 

Oblongata, 212. 

Spinalis, 40. 
Membrane, Basement, 25. 

Cerebro-Spinal System, 228. 

Gastro-Pulmonary, 28. 

Mucous, 28. 

Serous, 27. 

Synovial, 27, 53. 

Urinary, 28. 
Mesentery, 116. 
Mollusca, Definition of, 67. 
Mouth, Structure of, 103, 110. 
Mucus, 116. 
Muscles, Anatomy of, 73. 

Histology of, 79. 

Chemistry of, 81. 

Physiology of, 83. 

Hygiene of, 89. 

Intercostal, 193. 

Striated, 80. 

Non-Striated, 80. 

Voluntary, 83. 
Mucin, 32. 



INDEX. 



321 



musculin, 31. 
Myocomma, 101. 
Myolemma, 80. 
Myology, Comparative, 98. 

Nails, 280, 288. 
Nasal Duct, 269. 
Neurin, 83. 
Nerve-Cells, 225. 

* Centres, 210, 230. 
Nerves, 81, 210. 

Cranial, 219. 
« Cutaneous, 277. 

Spinal, 223. 

Sympathetic, 224. 
Nervous System, Anatomy of, 210. 

Histology of, 225. 

Physiology of, 229. 

Hygiene of, 240. 
Neurology, Comparative, 252. 
Nitrogen, 31. 
Nucleated Cell, 14. 
Nurse, Duty of, 199. 
Nutritive Apparatus, 103. 

(Esophagus, 107, 112. 

Oil-Glands, 279. 

Olein, 33. 

Optici Thalami, 215. 

Organized Bodies, 12. 

Osteology, Comparative, 67. 

Oxygen, 34, 199. 

Papilla, 262-276. 

Palate, 110. 

Pancreas, 109-112. 

Pancreatic Juice, 119. 

Pancreatin, 32. 

Parotid Gland, 107. 

Patella, 46. 

Peduncles, of the Brain, 215. 

Pelvis, 42. 

Pepsin, 32. 

Peptones, 32. 

Pericardium, 150, 156. 

Perichondrium, 186. 

Perimysium, 80. 

Periosteum, 52, 60. 

Peritoneum, 116. 

Perspiration, Uses of, 287. 

Pharynx, 107. 

Pleura, 185, 188. 

Pneumonology, Comparative, 205. 

Poisons, and their Antidotes, 303. 



Portal Vein, 141 . 

Protoplasm, 14. 

Proximate Constituents, Organic, 30. 

Inorganic, 30. 
Pyramids of the Brain, 213. 

Radiata, Definition of, 67. 
Bespiratory Organs, Anatomy of, 183. 

Histology of, 186. 

Chemistry of, 188. 

Physiology of, 190. 

Hygiene of, 197. 
Retina, 266. 
Rooms, Ventilation of, 198. 

Warming of, 201. 

Sacrum, 43. 

Saliva, 117. 

Salavin, 32. 

Scapula, 43. 

Secretion, 178. 

Semicircular Canals, 271. 

Sick Room, 300. 

Skeleton, 36. 

Skin, 274. 

Sleep, 245. 

Sleeping Room, 199. 

Sound, 285. 

Smell, Sense of, 262. 

Spinal Cord, 212. 

Column, 89. 
Splanchnology, Comparative, 131. 
Spleen, 109, 115. 
Starch, 34. 
Stearin, 33. 
Stomach, 107, 112. 
Sweat Glands, 279. 
Synovia, 59. 

Tarsus, 47. 
Taste, Sense of, 260. 
Teeth, 105, 111, 122. 
Tendons, 81, 85. 
Thoracic Duct, 140. 
Thorax, 38. 
Tissues, Adipose, 21. 

Areolar, 18. 

Cartilaginous, 19. 

Connective, 17. 

Fibrous, 19. 

Muscular, 22. 

Nervous, 23. 

Sclerous, 21. 

Tubular, 22. 



322 



INDEX. 



Tongue, 110, 261. 
Touch, Sense of, 274. 
Trachea, 184, 187. 
Tympanum, 272. 

Ultimate Chemical Elements, 34. 
Ulnar, 43. 

Uriniferous Tubules, 181. 
Uvea, 265. 

Valves of the Heart, 158. 

of the Veins, 159. 
Veins, 154, 159. 



Veins, Portal. 155. 

Pulmonary, 155. 
Ventilation, 201. 
Ventricles, of the Heart, 150. 

of the Brain, 216. 
Vertebra, 39. 

Vertebrata. Definition of, 67. 
Vestibule, 270. 
Villi, 122. 
Vocal Cords, 186. 
" Organs, 183. 

Watcher, Duty of, 302. 



THE END. 



